My tip for allocating skill points. Only invest up to a certain skill, then stop investing points till you have enough for the next skill.
For example, in the sword skill line...
13 - Metal Slash
22 - Critical Hit Rate Up with Sword
Invest up to 13 points to get metal slash, but if you don't have enough points to get the next skill, don't invest those points.
An hour or so from now you may think to yourself that you'd rather use whips/bow/spear/etc. instead. If you had invested all your points as soon as you got them, you might have 17 points invested in the skill tree which you don't plan to finish. At least 13 points are going to actual skills, but the other 4 have gone completely to waste.
This goes for any skill line. Early in the game I found myself changing my mind about weapons/skills I wanted my guys to have. Saving points gave me a head start in investing in their new line and I didn't feel any went to waste.