For the past year, I've been running a Gumshoe game with one really major house rule: All the skill pools refresh automatically at the start of every session. It's a simple change, but made the game a lot more enjoyable.
With this rule, there's no need to track from week to week how many points you have left/available in Chemistry (or whatever other skill is critical to the task at hand). I've found this does a great job of simplifying things, and freeing up the players to actually use their points. There's less book-keeping, and as a bonus players spend less time and energy agonizing over mechanical decisions.
In straight Gumshoe without this house rule, I tend to see players hoard points. Usually, they start out the campaign spending freely, but eventually they burn a point on something frivolous that turns out would have been really helpful 2 sessions later. After that happens once or twice, the players hoard their remaining points for weeks on end, then wrap up a scenario with tons of unspent reserves. This is far from ideal, and tends to just leave everyone feeling like the game didn't quite come together.
My houserule nips that problem in the bud, and gets the game rolling. Players feel empowered to spend points at any time. The result is characters that feel highly skilled, proactive, and very competent. As soon as they've identified a problem, they're already on top of the solution. I happen to like that.
Of course, this freedom to spend the points without drawback, means that PCs need a lot fewer points. Default Gumshoe (Trail of Cthulhu or Esoterrorists) give the PCs 60 to 65 General Points and 16 to 32 Investigative Points, for a total of around 80 or 90 points. I gave my PCs in the current campaign less than half that, a total of just 32 points each, split between the two categories, with lots of other restrictions on top. In hindsight, I could have trimmed that even further, probably down to 25 points per character since it's a low-combat campaign and our sessions are only 3 hours long.