A tip for handstand
One of the things I've found that's helped is to make a V shape with the legs. This helped me when I first learned supported headstand, and again in forearm stand when I started working with that, so it was only natural that it would serve me well in handstand practice. So a V with the legs is my first tip.
Using a wall for handstand practice
Use the wall, but not the regular way. Most people kick up to the wall. This is totally cool at first when you're just getting used to being upside down, but after that, I'd love to see people turn around and take it the other way.
1. Stand far enough away from the wall that when you lift one leg, the bottom of the foot hits the wall.
2. Then, turn around and put your hands down, shoulder distance.
3. Carefully step your feet onto the wall. Walk your legs up the wall until you feel your pelvis is over your head. You might need someone to watch you and tell you when you've hit the mark because it's hard to feel if you're not used to it.
4. Carefully lift one leg. Go for the V shape, not the straight up and down handstand. The V shape will help you find your balance, and so long as you keep your bottom leg toward the wall and come up slowly with the other leg, you won't tip over.
5. Maybe, just maybe, step that lower leg away from the wall and try to find your balance in handstand. Breathe, breathe, breathe and then slowly come down with control.