Building habits is a good way to get out of the rut.
Depending on the the time it could be fundamental to analyze the board and the opponents move to gain a general sense of the direction and goals of each side, of course this is most likely acknowledged by you.
A way to reduce blunders is to manage time, which imposes how you multitask.
If anything, multitasking isn't as much about the ability to effectively tackle on each individual thing, but of being well acquainted with certain aspects so you can focus on certain parts.
Certain sports such as football have many dynamic aspects, but certain things practiced heavily become more natural, such as throwing/ catching, which allow you to focus more on field awareness, position,and the oncoming defenders.
Following this it may be helpful to practice tactics by playing a bunch of chess tactics on chess.com, lichess, etc, or playing chess engines that follow similar moves so you can expand on your knowledge of the systematic processes in opening.
Generally following/ or making a system before playing may help too (analyzing undefended pieces in your side, blundercheck, etc)
Listen to Music
Another thing is it could be useful to listen to music while playing. I personally listen to jazz, classical, or lofi hip-hop while playing. Something calm and relaxing so I'm not as impatient, and aggressive when I play. Something without lyrics is awesome, and can help tame part of your wandering mind.
Though I do expect the use of headphones would be banned in tournament play.
You also have to take into account the type of chess you are playing
Using FIDE standard for Classical Chess, which allows an hour and a half for the first 40 moves and another half an hour for the rest of the game, you have a large amount of time to calculate. In this variation major blunders are pretty much absent at higher level play, as the players are able to completely analyze their moves, anticipate responses, calculate lines and attacks, and even delve into intrinsic theories of the board/ color/ control/ etc.
With 10 minutes to an hour you have a fair amount of time to analyze your moves and board. I personally find this variation ends with who has the stronger end game moves, so with standard opening principles I like to spend half of the time in mid-game setting up a strong, preferably 2 rook, or rook and bishop ending with a faster king centralization
Blitz is 10 minutes or less, commonly played with 2,3 or 5 minute variations. With 5 you may not have a large amount of time to analyze the opponent's goals and motive, but you should still get a general sense of why they make each move. Personally a quick blundercheck in mid-game, 2-5 seconds, and you should be good, just check common moves like how the position could be exploited (fork, discovered attack, skewer) and structure (pawns, defended pieces).
In the 2 and 3 minute variations it is common to find weaker, less analyzed moves, with stronger players still rarely making blunders. The key to this is memory and intuition, with a large history of chess allowing you to find similar positions, piece combinations, and ideas. This variation is heavy on tactics with both sides waiting for the other to make a blunder or a weaker, exploitable move. The harder part is implementing strategy, but with study of the piece combinations, and chess theory you can practice powerful, unexpected attacks that could force the opponent out of their comfort zone. So using this the key to making less mistakes in this variation is practice, and with the above allusion to football, make tactics inherent.