It's hard to beat the little impedance meter boards on eBay for about $25 now. If ?you have a scope and signal generator, you can build a traditional bridge circuit with just a few parts. The reference will be a small close tolerance film cap that should be easy to find. There's a plan for a simple but accurate bridge here-
and lots more cap fundamental stuff here-?
Aluminum electrolytic caps show various odd effects with frequency, but at any single frequency the simple series or parallel models work OK. The standard frequency for measurement is usually 120 Hz, where losses will be low. At 1 kHz or more, you'll see losses increase greatly and Cp will serve you better than Cs.
