Tactics won't raise if you're trying to hunt monsters that are above it's level. For example if you're hunting dragons with 60 tactics then it won't raise.
The way I like to raise tactics is to buy it to 40 in NH, train it to 50 on the quest, then go straight for a 6gp wrestle until the gains run dry then move onto a 8gp wrestler. Once the gains run dry on that (80ish), you can either move onto a paladin or a golem (with a poison weapon). This will take you up to and beyond 100.
If you wanna do it through normal gameplay, I'd say grab a fast weapon and go and rip through the spawn at Despise or Deceit.