Before the Match: On-court

What the ITTO saysWhat this looks like in practiceFurther advice / good practice / additional considerations
Carry out the toss fairly and ensure that the winning and losing sides exercise their choices correctly and that they are noted.If the umpire and service judge have arrived first, the umpire should stand on the singles side line, on the side with the umpire’s chair. The umpire’s feet should be on either side of the short service line (on the side of the net that is closest to the referee or match control). The service judge should stand beside the umpire (between the umpire and the net).

If the players are already warming up on court, stop them in order to carry out the toss. (This may be more common in smaller events, whereas in larger events, players and technical officials often march on court together.)

Ask the side that wins the toss to make the corresponding choice (serve, receive, or choose a side). In the case of doubles, if they choose to serve or receive, ask which of the pair will be the server or receiver.

Ask the losing side to make the remaining choice. Again, in the case of doubles, ask which of the pair will be the server or receiver.
As you are doing the toss, make sure you can properly identify each of the players. If necessary, make a note on your scoresheet to remind you which player is which (e.g., red shoes, ponytail, blond, knee guard, etc.).

If there are no line judges, inform the players whether you will be calling the lines or they will call their own lines. This can help avoid misunderstandings or conflicts later on in the match.

If players are calling their own lines, they should know that you will be able to overrule them if necessary. Adding that “you hope not to have to do so” is a nice way to proactively ask for good conduct and sporting behaviour, and can help players feel like you are all working together.
On the scoresheet, write “0” for both sides and “S” for server, and in the case of a doubles match, “R” for receiverSee the instructions in Section 7 of this manual for more details on how to use the scoresheet.Remember that the “R” for receiver is only used for doubles matches. In a singles match, it is evident who is receiving.
Get into the umpire’s chair as quickly as possible after the toss,
start the stopwatch and then…
Get into the umpire’s chair (if applicable) and complete your scoresheet as appropriate.

Make sure you have marked down who will serve first and, in the case of doubles, who will receive first.
Have a look at the players’ bags/belongings to make sure everything is put away as required (for example, in baskets courtside) and that there are no liquids that could spill or other hazards.