Main tip is clean the area of application well before applying the "Command" strip. If you do that, let it sit for a hour or two before you hang anything on it, it will stay in place for a long time. I have some of the larger ones hung on each side of the walk around bed and we hang mesh bags we use for dirty clothes on them. For a week long camping trip, they can get pretty heavy, maybe 25-30 lbs. They have held up for almost 18 months now, through the heat of the summer without problems.
Also love the Velcro command strips. Use them for normal 8x10 wood picture frames on the walls. One strip in each corner and they have not moved . I used to double check them each trip before and after arriving and not so much as being a little loose. Don't even bother checking them any more. Makes it nice for hanging pics from out different adventures.