Haven't had any leak issues yet and these are my main daily diapers, what I do is fold the diaper in half length wise before putting them on. While putting them on I lean up against a wall with the back of the diaper all the way up to the small of my back (about 3" past the top of my butt crack) I then bring the front up put I pull it up and out using both hands, one on each wing, I then tape in place, being careful not to over tighten one vs the other, I then run my fingers threw each leak guard to make sure there standing up.
I notice diapers fit differently when you put them on standing up vs laying down. If I put one on laying down I will get leaks, especially with larges, but mediums work pretty well to put on laying down. If I put one on standing up larges fit great and mediums are way to small, its very weird. FYI I'm 6ft about 34" - 35" waist and weigh 185lbs. Fairly thin and tall.