I only used RTH on my first flight- I now pretty much always use manual control to bring it back. I find it gives me more confidence in controlling it. I'll keep RTH for emergencies, otherwise I like manual flight. I've had one minor flyaway where I was using activetrack and my Hoverbee just went 'Welp, I'm bored, bye!' and started to back away from its target. I pressed pause and then reduced its height before putting it back into normal mode.
I have a local park which is just a big flat field surrounded by trees- it's perfect for practising. It's a bit boring, but I can try out different modes and experiment, but be certain I'll only hit a tree if I get a flyaway. I've also tried a sort-of simulated flyaway by using tapgo or activetrack to send the Spark in a random direction, just to sharpen my muscle memory and give me better reflexes in the case of a real flyaway.
If you're scared of flying, a big boring field is a good starting place! Also, don't panic if you crash- Sparkie is built like a tank and can survive a lot of abuse.