- long range rail fights
- close combat rail fights
But the problem is, that you not necessarily learn how to play if your opponent isn't holding a railgun too. Railing becomes different if someone charges you with RL/LG/PG or you always have to fear someone comes up behind you with a appropriate weapon and you still holding the railgun. In insta its only rail vs. rail. But real railskill in other modes like duel, ctf, tdm, ca is deeper. Most good insta players don't hit the same high accs in other modes.