While I have a primary project I'm on, I do tasks for three other managers as needed. If I'm not motivated to work on one task, there's always another.

The downside to this is being told by three managers that each task had the highest possible priority. [This happened once; I then conferenced them together and asked for them to rank the tasks. They answered simultaneously "*You* know what's important!". *sigh*

Generally I write a program from the top down, with dummy low-level routines. Once I can see the scope of the task, the details generally become easy to implement.