I love using the Recom DC-DC Step Down converter (r-78b5.0-1.5) in place of a standard 7805 5v regulator, with Power Supply Option E: http://www.midibox.org/dokuwiki/doku.php?id=wilba_mb_6582_psuopte   It's super efficient @ ~94%, so it doesn't require a heat sink, but it's a bit expensive @ ~$10.23 USD: https://www.mouser.com/ProductDetail/919-R-78B5.0-1.5   I noticed that you can find super cheap DC-DC converters on AliExpress for only a couple bucks: https://bit.ly/36LB0q9