a little generic... anyway you could try expose your point of view on forum or communities you are interested into, the more you expose your point of view the more you will have a chance to find what you are searching
Don't think is possible to give a right answer, it depends on the context of the problem, 200 lines for a html generation script is one thing, different if it deals with more complex stuff (let' say algorithm or low level stuffs)
A good way that works for me is dumping on a piece of paper what are you open point at the moment you are left, could not be the best (or only way) to handle it but it's fine .
Eg. Yesterday i've been working on a web form
Before to leave:
- Check if Button x behave as described by req.1
- Add javascript alert on button y click
- Verify that procedure x works for a given impunt