When to WS

[Arcon]

Typically 100% gives you best results. There'd have to be a 201% and/or 301% increase in damage or more in order to warrant saving TP to 200% or 300% respectively. No weaponskill offers that level of improvement on the output.

This sums it up. If you want to know the TP modifier by weapon skill, simply look it up on wiki, normally the TP multiplier is listed for every WS. Also remember that WSing also returns TP, if conserve TP kicks in, it can be quite a bit. The only reason to save to high levels is either to use it in combination with Sekkanoki (you'd want 190% or more for that) or storing up for a boss zerg, when you wanna dish out as much damage as possible over a short time.