my method if you can picture this - standing up straight, feet bit wider than shoulder width apart, arms out wide horizontal to the ground (like a star jump position) reach sideways down to the the side of your knee or lower down the side of your leg (keeping your back straight and not leaning forward or back) start slowly one side then return to standing straight up, then do opposite side. slowly increase the speed alternating from side to side without stopping between sides. this usually gets quite a few loud hip socket pops for me.

I normally crack everything myself, however, sometimes there are things that need cracking that you just can't do yourself.
I have found that the chiro will normally fix the bits I can't get to and they normally give you a good all round body crack that you just can't do as effectively yourself.
Plus you learn a few tips and tricks that you or your partner can try next time (some cracks are best done with the help of someone else).