This masternode tutorial was quite useful:
https://medium.com/@rmarle70/desire-masternode-setup-guide-ubuntu-125b148280ba

Additional comments and tips:
- no need to build Desire from scratch, just download the tar.gz release
- you can’t use Ubuntu 16.04, use 14.04 (some libs aren’t compatible)
- secure your VPS! (UFW, Fail2Ban, limit SSHD to key auth, disable root)
- use SSH key authentication and elevate with sudo if necessary
- keep your VPS up to date with unattended-upgrades
- UFW: tcp/9919 from anywhere, tcp/22 from your IP

- install the sentinel as well
- the sentinel requires additional settings in desire.conf
- the RPC port should be different from your daemon port
- generate complex RPC username and password