I thought the rule of thumb was 1 per foot plus 1 as a starting point. Never heard that was just for spinning rods though.

Jeff you're bound to get a mix of theories, but they will all boil down to doing it 4 different ways:

1- use the chart specified by the mfg. (always a safe starting point)
2- do a static test to determine number of guides and their placements.
3- use a formula to figure out a custom spacing.
4- do whatever the h3ll YOU think looks and works right for you.