how to do a fair giveaway?

hello, I was wondering what is the proper way to do a giveaway as you said you would do it between followers who did mention 3 other accounts and liked the post?
inserting all data in excel takes a lot of time, I wanted to know if there is an automatic tool that can do this?
and also, when you filtered your list, is there any random selector for this purpose?
thanks

there's a few free(mium) tools out there. check out @CryptoGenius 's very recent thread:
https://www.blackhatworld.com/seo/method-how-i-got-28-000-people-to-participate-in-a-giveaway-contest-in-less-than-20-days.1131988/

I found this, must be useful please check https://sharethis.com/best-practices/2018/04/instagram-giveaway-examples/