Neck Stall
In my opinion, neck stall is one of easiest soccer trick. It's hard at first but once you get the hang of it, it'll be a snap.
Neck stall can be done by placing a soccer ball on your neck and balance it for as long as you can.
Beginner's Level
1. Place the ball on an even surface of your neck. Find a spot where you feel the most comfortable at. Then balance it for as long as you can.
2. Flick it up by letting the soccer ball roll down on the back of your head for about 3/4. Then flick it up and catch the ball.
3. Repeat the same steps again.
Intermediate Level
1. Throw the soccer ball at a reasonable height.
2. Catch the ball by letting it stall on your neck. A good timing and execution should improve this.
3. Once you've neck stalled it, flick it up and catch the ball.
Advanced Level
1. You can start by doing a foot stall.
2. Flick it up at head height.
3. Catch by doing the neck stall.
Tip: Your body needs to bend in 90 degrees to achieve a balance on your neck
4. Flick it up with your head and catch the ball.
5. Repeat the same steps again.
For the advanced level, my suggestion is to start from foot stall because it's the easiest and the most obvious freestyle soccer trick combination. There are other types of combination you can compile on like head to neck stall.
So there are 3 levels to improve your neck stall. It does takes time and with practice and persistent, you should be able to do it with ease. Hope that helps!