What's an effective way of explaining the difference between 思想 and 想法?
If you want to express "We share quite a few ways of thinking", you can say "We have lots of similar 观念", which is short for "思想观念"。

Or "观点" / "看法", point of view.

"想法" is usually used in a sentence like "I have an idea to do something",
likely to combine with verbs.

"思想" is a general term.