Which are examples of trustworthy ripple paper wallets? I've been reading on the internet and I have found several websites for generating ripple paper wallets: ripply.eu, bithomp.com, gatehub, ripplepaperwallet.com, etc. But I'm not sure which sites can be trusted.
Looks to me like https://bithomp.com/paperwallet/ seems to be safe, but if you're really worried about generating public & private keys online, I would recommend you to download the source code https://github.com/OctillionSA/ripple-paper-wallet and run it in an offline computer
You should not use any website while connected to the internet.
1) Save this website(CTRL + S): http://ripplepaperwallet.com/
2) Open saved the website in a secure environment and then generate your wallet.
You can find the steps in detail here: https://www.reddit.com/r/Ripple/comments/6f4juz/psa_how_to_make_a_paper_wallet/?st=jcal6r88&sh=32e45553