I had to drop down and fix a place where I got off one. I used EZ's method of marking with a safety pin. I guess it wasn't obvious enough for me in dim light. Then I wondered why I had a different number of sts on one front from what was on the other. I had the right number of sts overall, though! (If the overall st. Ount had been off, I might have had to frog!)
The yarn dangles on each side of the st you use for increasing and decreasing. I can't remember who came up with it, but it really helps. When I get to it for increasing I take it out by pulling it, M1, then lay it over the space between the needles but OVER the working yarn K1, bring the other end of the dangling yarn to the front, then M1 for the other side. When you get ready to increase again at that point, it will be down one st, but it's easy to see which is the st directly above it.