We've just started using these last week, DS is 8 weeks.
No matter what I try we always seem to get leaks. Always at the legs. I've watched several videos on fitting, he's on the smallest rise, hip and waist settings since he's at the bottom end of the weight range but he gets awful sock marks. They do fade after 5/10 minutes.
I make sure the back is almost giving him a builder's bum, pull the side tabs up to his armpit and over, and squash the middle part when pulling it up and tuck it into his leg creases as best I can, however it always seems to have moved down his thighs when I come to take his nappy off.
I even emailed the company for advice and sent pictures but they said it looks good and just reiterated the things I'm already doing.
Has anybody else had the same problem with leaks? It's driving me nuts. The only thing I can think of is that I'm only using one booster as he's so little still, I didn't think I would need two yet but maybe I should give that a try?