it took me a while to get them on my new skis (bridges) because they're pretty stiff, so i bring one ski back first. Get pretty stable on the first ski, then bring back the other. But if you're on flexy skis, all you really do is lean forward and tuck your knees
and as for popping out, all i had to do was tighten up the din on my bindings. If it still happens, try to get up quicker, because if you've got all of your weight forward for too long, you'll pop out either way.
put your poles by your tips. put weight on them. throw your body forward so only a bit of your tails are coming off the ground. bend your knees and bring em up.