I use calipers and measure a bunch of different spots. I found an excel spreadsheet a few years ago that has 8 BF caliper-based formulas in it. So I log the results for a variety of spots and it populates the numbers for all 8 different formulas and gives me the average number. Works pretty well. I check it every Friday.
I got a new Taylor 5579s scale at Sam's Club for $20. It is really
cool looking and weighs to the nearest 0.2 pounds and shows % body fat
to the nearest 0.1%. This is much better resolution than my old Tanita
scale which was to the nearest .5 lbs and 1% on body fat. Don't know what my
REAL % body fat is! Tanita says 18%, Taylor says 28.1%, and Fat2Fit
calculator (http://www.fat2fitradio.com/tools/bf/) says 21.5%. Consumer
Reports says body fat scales aren't very accurate.Then I decided that working out 5-6 days per week must qualify me for the
"athlete" setting on the new scale. With that, my body fat reads as
22.5%. Much closer to my other two reference points (and less of a slam
to my psyche.) I can say the Tanita readings reflected my weight loss progress for the past several months, but I don't think I would count on any body fat scale for an estimate of my "true" percent body fat.
I use the Withings scale. So nice to have the numbers automatically uploaded! On occassion I get a wonky body fat %, but I don't take any single number very seriously. I watch trends/averages over time. I'm not as concerned with my specific body fat % as I am that it's (slowly) moving in the desired direction.