I don't track it, currently. When I have in the past I used cheap-o calipers, specifically Accu-Measure. As it happens I recently had my body fat measured by several methods, including multi site calipers, multi site measures, bioimpedence (hand held) etc. (No scales, sorry.) We didn't have access to underwater weighing or bod pods or anything fancy like that.
The results were, everything gave very similar numbers, and were all within the margin for error of each other. Interestingly, Accu Measure brings me in at about 3-5% lower than any of the other methods, which sort of confirms my suspicion that it is biased low.
My point, I guess, is that there are many useful methods you can use at home; my suggestion is to pick ONE and use it for comparisons/tracking only; also remember that there is a margin of error in EVERY method, including the gold standard methods, so don't be too hung up on the number itself.