This may count as advice to myself more than anything else, but since I've given it repeatedly, I might as well write it down.
A "tweak" is a change to how a program looks or functions which is very small. It might be defined as the smallest change which could result in a noticeable change in form or function.
Every so often, you (I!) will notice something that doesn't quite work right. Or it works, but not as wonderfully as it could. We live in an open-source world, so you may have the power to tweak it so that it works better, or looks better.
- Go ahead and make the tweak.
Do that as soon as convenient after you feel the itch. If it's really a tweak, it won't take very long. The XKCD about saving time applies.
- Test the tweak.
If you didn't test to make sure that the tweak (a) works (b) doesn't screw something else up, you might as well not have tweaked.
Once you have made a tweak successfully, you will nearly inevitably notice something else that could be tweaked. Don't do it. Your technical intuition was probably good about the worthiness of the first change; it is now intoxicated by the heady fumes of success and cannot be trusted. Wait until it really starts to bug you. In the meantime, get something else accomplished.