i'm sure after i post this everyone who reads it will be like "i've been doing that for 30 years", but it was sort of a revelation to me..... anyhow, i find that tuning the reso head a third higher than the batter sounds great...BUT!!... it is hard to tell whether they are the right pitch relation... you know the old "bing bong bing bong"... anyhow the other day i started tapping the two heads simultaneously... you can really hear whether the two heads are dissonant or if they are forming a chord... works like a charm i find... of course you have to get the two heads tuned individually first... no tips for that... good luck!