It all depends on the bow.
There is the bows amount of center cut, performance of the bow, draw length to take into consideration.
There is no magic formula. I have 60# bows that have to have light spines and a 45# that takes a heavy spine.
You have them to try them with 100 gr brass inserts and heavy point weight. Leave them full length to start.
Points are cheap, so get some from 175 to 250, or if you feel adventuresome make up some SCUDS. 200 gr brass Ace points, 125 gr steel adapters , and put those in to the brass insert. That will knock of the spine to a managable level. I shoot these and for broadheads to match I use a 200 gr ace with the 125 steel adapters. They hit with a thud a deaf man can hear.
Dennis at
http://git-r-donearchery.com/ , a sponsor here has lots of the points and adapters, and some good deals on carbons.