If you notice a crack starting to form at the seam between your wall and baseboard, you shouldn't just paint over the top — that won't fix anything. Instead, add a new layer of caulk to help fill in the gap.
These instructions for how to caulk a bathtub are super easy to follow and will give you a perfectly straight and tidy caulk line, just like the pros. If you need to know how to caulk a bathtub, READ this first! This blogger tells you what you SHOULD and SHOULD NOT do!