How should someone prepare for a chess tournament? Openings? Tactics? Strategy? Endgames?
What are some of the techniques strong players use in order to get ready for an upcoming tournament?
If the opponents are known (e.g. in a round robin tournament) you can prepare specifically for these opponents, i.e. find openings or positions which your opponents don't like or in which they perform badly, etc.Professional players would do this even during the tournament (in-between rounds).
If the opponents are not known (e.g. in a large open tournament) there is not much you can do other than what you should always do: practice tactics, learn/study endgames, strategy, refreshing your openings, doing some sports (not chess)...
Overall at your level I would not worry too much about all this. Arriving relaxed to a match will be more important than trying to prepare specifically for one opponent.
Openings can be trained with applications like chessable.com, and if you're going to be playing in a tournament, then it's probably assumed that if you want best results that you're going into it with a plan. What this means is that you're going to play your pre-determined openings and thus openings should not be a major area of focus in your preparation, at least at your level.
I use chessable as an everyday practice so that I always know what to play in response to my main lines. Yet, this doesn't take much time to do. At your level, I would recommend tactics over openings, but still incorporate chessable into your regimen.
Endgames are critical to reaching higher levels, so they should not be left out. Again though, at an 1800-level, endgame study can certainly help but typically at this level I've found that it's more about the middlegame than anything. For example: tactics resulting from your pre-determined openings, and lacking a clear plan of what to do when a desired position is reached, or recognizing key features of a position and acting on them. For example:
So in the end, I believe at your level tactics training, overall middlegame strategy and recognizing positional features are going to play an important role in tournament preparation. Sprinkle on some endgame study and do your daily chessable training (openings) and you're good to go.
Also keep in mind retrograde and post-mortem anaylsis; using the completed tournament's results to learn from. Using this analysis, you'll hopefully learn from your mistakes and not make them again in future tournaments.