I was trying to fly an approach into St. Maarten today (which was interrupted by a fatal error which crashed FSX about twenty minutes before I would have landed), and I saw that TNCM does is not equipped with ILS, but rather you must fly either a visual or VOR approach. Which is typically used by airline pilots?

Well, unless corrected by the rw Captains, I'd say that your approach type depends on the equipment you have available, on the plane as well as on the ground.
When it comes to short ATC handling aspects, a visual approach may give you the most freedom of movement and also adds flexibility to the ATC's restrictions.

But I think your question was pointing at the 'which one may be the most appropriate?' aspect in the case of TNCM having all ground based stuff running.

Now they don't offer any precision approach procedure there, only some non-precision approaches are available.
The RNAV (GNSS) one is a LNAV +V type, so the vertical guidance only has an advisory character and you can only fly it down to LNAV minimums, which gives you a MDA of 700ft in our TNCM case.

The VOR approaches offer a minimum of 500ft MDA, so, while still being a non-precision one, we may call it more precise.
Since the 757 and 767 can't track a VOR radial with their AP modes, you may be using something way more precise on those occasions, which is the FMC itself.

As Peter pointed out, the database should give you a selection with waypoints and constrains, so you would remain in LNAV and follow those segments, while you can set up and monitor the raw VOR data on the FO's side.

So see yourself using the VOR Z Rwy 10 approach for example, your FMC has the approach loaded and LNAV is active, your Captain's side stays in the map mode and your FO's side monitors the raw data from the VOR.
In this mode you can descend down to 500ft altitude. The rest is done with the visual reference, so please leave the tourist guys at the beach intact.  

The altitudes and distances are shown on the chart or come from the navdata, so VNAV may be an option or you just use the VS wheel to comply to the values.
This should all work nicely with the CS planes and also offers you two separate systems to monitor your progress.

Since you remain in LNAV for the lateral guidance, the FMC is completely independent of any VOR raw data. So even if TNCM turned that thing off, your FMC wouldn't be shocked at all.
Same goes the other way around, if your LNAV would become unreliable for whatever reason, the raw data can still be used.
So, either way, you may at least get close to the beach. 

If the tourists on the beach suddenly run away when seeing your plane, you are 'slightly too low', I guess. If they look bored, 'way too high'. Staying still, cameras ready = 'on the glide'.
Give them a show!  

Oh that FSX ATC, mysterious ways.  

I haven't used it for years, but I think "they" always vector you, no matter what. If there is terrain, it won't care much and since STARs and approach procedures usually avoid terrain or take things like proper separation possibilities into account, this may well conflict by design.
The AI planes fly those strange paths too.

I would recommend a program being capable of procedures or at least aware of them (remains silent on the actual procedure) for this, or online flying, which is the best in my eyes.
Or, complete silence, which is great too.  


On that descent rate, you can gain awareness in many ways.
From the concept, the standard approaches aim for a 3 degree descent. Now you know!  

As a rule of thumb, you will look at your groundspeed, lets say 160 knots, add a zero (x10) and then divide it by two. 160(0) / 2 = 800 ft/min. That's the rate you should aim for to be on a 3 degree downward path. You may add another notch on that VS wheel since your rule of thumb aims a bit low there, so 850 or 900 ft/min may be more appropriate.
Don't mix those degrees up with any pitch attitude shown on your instruments. Your aircraft's nose points at one direction, while the plane itself can travel along a different path and this path forms the 3 degree angle towards the runway.

Where else could you get the necessary descent rate?
Looking at the (approach) charts, the lower right corner offers a small table with examples of possible groundspeeds.

Those values are calculated, so no thumbs included, but some trigonometry. As a matter of fact, they show you a precise rate to aim at, so on our 3 degree approach, we will see something like 849 ft/min for a GS of 160 kts.
Remember the 'add one notch' thingy? There you are!

Another source is your capable plane and its FMC.
If the thing has VNAV, it can "draw" you a path right to the threshold. What it needs is some basic data, like the aircraft's groundspeed, its current altitude and later height and the point were planet Earth starts again.
Most of this stuff will be there, without any input from you. With e. g. the Flight Director enabled and VNAV connected, it will point to a pitch attitude where the plane stays on the desired path.
Also, the deviation scale on the ND comes up.

That thing can be a bit touchy in regard to the VNAV implementation, but since we are in the sim, no real persons (only egos) will get harmed.  

To monitor your rate of descent and the point where the commanded altitude on the MCP will be reached, you can also follow the green arc on your ND. It will point at the spot ahead of you, where the plane and the commanded altitude will be on the same level.

Test it, raise the nose slightly and it will move further away. Lower it, and the arc will come closer if aiming for a lower altitude. Dial in the runway's altitude rounded to the next 100 and place the arc on the threshold.

Still, you are trying to shoot for that 3 degree approach towards the runway.
Any altered angles, for other approaches, can be read on the corresponding charts, together with the mentioned calculated values.
Be aware that anything above 5.5 degrees is a tough task for an airliner as the descent rate for our 160 kts groundspeed example e. g. rise from the shallow 849 ft/min to a whopping 1573 ft/min.
With that much vertical speed, there's not much headroom for trying to slow the plane down, so you will come in there fully configured most of the time.

That 5.5 degree approach can only be flown by certified planes and crews, so that's a special chapter and I think some of the other guys will have some neat examples for that stuff.

If you combine the things from above, you should be fail-safe in case anything of those things was wrong.
The guys like Lou will see if the approach is correct, they've done that often enough. The sim guys suffer from a more or less flat perspective and, of course, from way lesser experience.
If you often switch the planes, this also adds on the distracting side.

Of course, if you alter your groundspeed and for example slow the plane down, your VS has to be altered accordingly, the value gets lower. Got some tailwind and the GS suddenly goes up? VS has to be increased, and so on.
That's the experience and pilot part then, although that drawn path from the VNAV will of course help you, same goes for the green arc.


Have fun.  

Was there last Spring on a cruise. They make it look so easy!

http://vimeo.com/29869004

The thing is that the FSX ATC doesn't know about SID and STAR routing. That's some data which changes over time and also is different for every airport, so the generic ATC approach of the default implementation fails there.
Since they've planned it to be basic (and for that, it's great), it always assumes that you like to be vectored to the point where you are able to catch the ILS for example. That's a thing which can be done at any airport, but leads to the strange terrain violations from time to time.

Some approaches are programmed into the scenery files, those are the only ones FSX can read and handle. Some of them may be older, but they should be realistic. The default GPS shows them for example.

The most common provider for current navdata in sim spheres is Navigraph and your plane already uses that stuff. But this isn't generic at all, every airport needs a file, every file needs to be maintained, so it's payware.
The FSX ATC can not be updated with this method, so you would have to switch to another (addon) method or try the online flying, which is free of course.

Another thing which at least offers some rw atmosphere is to listen to live ATC while flying your own stuff. There are some free sites where you can pick different airports from all over the world, so you can pick the one you are flying to.

I've heard some pilot complaining about all that sissy stuff in modern cockpits lately.    

We at Moth Air never use the FSX ATC, we always circle around the light bulb to land.  

Don't make jokes about that company. Flying is serious business.    
We even land at St. Maarten with our flagship, and stay there!