If you go into a loop as soon as you send it, with plenty of power it's gonna be really powerful an pull you as the kite goes down. if you do these half heartidly its most likely to hurt when you land if the kite hasnt reached the top again. if you loop when you reach the top of your jump, the loop will not have as much power however it can sometime drop or pull you near your landing making you off balence. either way you learn theres no "safe" way. Looping on lands pretty dangerous.
It clicked for me in 20mph or so on my 8m doing average loops by going straight into it. a big gust came in an i just went for it in the gust, the kite got the the top and i had to start down looping it to stop it overflying. this gave me a really controlled landing.
my best advise would be to commit, try it first on a medium sized kite in low winds just so you get the feel of the loop then try it on small kites in higher winds