I had the exact same issue, and only on Saturday when the really good shop's employee came out with me and showed me proper form for mounting and dismounting did I really get comfortable with a proper height. To mount, you stand astride the top tube, put the right (if that is your dominant leg) pedal slightly north of horizontal, mash it hard, and use that leg to lift yourself to the saddle. Dismounting, you keep your right foot on that pedal, slide forward off the seat, and land your left foot on the ground. After spending some time doing it it becomes easier, and the pedalling itself starts to feel more natural.
Someone with more experience please chime in if I somehow got it wrong, but I too wanted to be able to put my feet easily on the ground while seated. Give it a day of practicing away from traffic and you should have it.