As a full disclaimer I am posting this on two other forums, the learn japanese reddit, and how to learn any language forum. I hope that isn't against the rules as I know some forums don't like that.

I have been studying Japanese for 1 year and I have learned many words a long the way. But for some reason, I still get my interrogatives mixed up and confused. I have just recently started doing conversation practice over skype with a Japanese native and this is hurting me a lot. By interrogatives I mean words like, 誰、どこ、どの、どれ、どちら、どれくらい、どのくらい、いつ、 etc. Do you guys have any good tricks or not getting these words mixed up?

I can't imagine getting them mixed up if you listen to/are exposed to enough Japanese. They're used all the time - it should just naturally be drummed into you?

If you want to memorize them quickly, don't memorize them in isolation, rather learn them in full sentences with an appropriate answer. Then, it's just a matter of time and exposure.

If you need a 'system' I guess you can just learn the d-words with the corresponding and very similar k-words:

だれ？　かれ。
どこ？　ここ。
どの？　この。
どれ？　これ。
どちら？　こちら。
どれくらい？　これくらい。
どのくらい？　このくらい。

いつ？　いま。

Perhaps a deck concentrating on specifically these words can help? See https://ankiweb.net/shared/info/496526742.