So...am I doing this right?
 

I tried my first key-off, coast, bump-start today. I was driving about 50mph, saw a light up ahead go red, turned it off and coasted/braked until about 20mph when I threw it in 5th and tried to let out slowly (but felt like I dumped) the clutch, causing the car to jerk and start, then put it immediately into neutral as I stopped.

Did I use the right gear? Do it at the right speed? In the right way? Also, should I coast in-gear when the engine is off to a complete stop instead of braking? Does this cause any serious wear that engine-on engine-braking wouldn't?

Thanks!
Dan

At that speed, you might want to start at 3rd or lower. The engine needs to speed up fast enough to start on its own, and in 5th gear, your car will probably be below it's normal idle speed.

Yes that sounds about right to me (I don't know the gearing on your car, you may have been going too slow for 5th gear). With practice you will be able to bumpstart so smooth you will have to look at the tach to make sure the engine is running :)

press clutch or put car in neutral
turn key to off position
turn key to on position
Coast
Select gear
lift foot off clutch
drive

20mph is still drivable in 3rd, so do I want to generally use the same gear to bump-start that I would continue in at a given speed? Was the jerk I felt because I used the wrong gear or is that inevitable?

I'd say you're on to something. Use the lowest gear you would drive with to bump.

Regarding bump starts... um, what about power braking and steering?

You lose steering and you have a backup for breaking, you should test both out on a deserted road before doing it in traffic, :)

around 20mph 1st is to low, 2-3rd should be good, 4-5 to high. if you put it in 5th at 20 it will run lower than idle speed 500-800rpm. its probably right in the middle of run/stall (its like holding the brake while letting the clutch all the way up- to much load and it stalls/bucks). And please be carefully to not lock your steering when turning key off/on.

I tried it in my sloped driveway a few weeks back and nearly drove my car off the mountainside. I was going 5 mph.

So as you can tell, I'm rather opposed to bump starting... lol.

I like to use a gear higher than what I will be driving in. Of course I have only 3 choices so my experience will likely be much different than yours.

90% of the time I will bump start in third gear. I have a manual clutch (no hydraulics) so it is very easy to tell when the clutch starts to engage. What I do is quickly let the clutch out just enough for the engine to start and then re-engage to drive. I think that is the most un obtrusive way in my car. If done right I don't have any jerking.