quickest way to use google trends for keyword research?

Remember it shows relative interest, not search volume. 100 just means the peak for whatever you're looking at, so it's for comparing, not sizing. Quickest useful routine: put 2-4 phrasings of the same idea in side by side, set the country and a 5 year range so you see seasonality, then scroll down to related queries and switch to rising. That rising list is where new topics show up before the keyword tools catch them.