I’m one of those people that does this ! I’m sure there’s a better way to do this, but when I’m on my computer I just google the name / description of the emoji and copy and paste it from there. Sometimes I’ll use emojis just to spice up the name, but others I’ll use them to unofficially create categories (e.g.  for anything movie related if it’s just a fun experience).

There’s also a couple sites that let you search for them a bit more directly - such as EmojiTerra or Emojipedia.