Key thing is don't risk losing silly marks. Make sure you check the players before the game and at least try to deal with issues like different coloured under shirts / shorts, sock tape, etc, and as an absolute minimum get all jewellery removed. Likewise make sure the observer sees you checking the pitch and nets.
Make sure you deal with dissent, and by that I don't necessarily mean caution every time someone disagrees with you, but rather be seen to be dealing with it. That could be a quiet word, public word, involving captain, or cautioning, but the key thing is you don't observe it.
And ensure that if there are mandatory cautions you deal with them. I'm assuming you are 7 to 6 so observers shouldn't be too harsh, but if a player belts the ball from one end of the pitch to the other in frustration at a decision and you do nothing, or even worse talk to him, it could count against you. Likewise if there is a blatant act of SPA, you need to be cautioning, and DOGSO is DOGSO no matter what level, what the score is at the time, or when it occurs. Don't do what one referee I observed did when he told me that he didn't send a player off for the most obvious ever act of DOGSO because it was the last minute and his team were losing heavily ..!
Above all though, try not to change too much from your normal game