ordered a bunch of these to give as gifts:

burner.pro

I'm eth newbie..just learning
(working on @farcaster)

terminally.online

would be fun to gift an fid this way though would need some work to make it smooth

Building @warpcast and @farcaster, new dad, like making food

purple Burner with a Warpcast invite code written on the front is not a bad start

I think that physical cards (especially if they are elegant, like these) with a QR code that include a paid FID invitation + follow pack are a great way to invite people. Relatively expensive, but handing an invite in person is sybil-resistant (and, my guess, harder not to use it).