If you start a tweet with the letters
DM
it makes Twitter send a direct message instead of just tweeting.

Very sorry to the twitter user with handle @is who (multiple times) received a direct message from me when I was trying to talking about being a Dungeon Master (DM) in the context of Dungeons and Dragons. Finally got the tweet to go through regularly though:

https://twitter.com/alexjgustafson/status/635116325325676544