This is as all of them are important to keep in mind before a presentation.
Practicing is important so that you are comfortable with the speech and with presenting the speech.
Memorising is also important so that you don't forget your speech, stutter or make a mistake and are able to recite it properly.
Getting input from others is important as they can give you valuable advice and ideas from their perspective (outsider's perspective) which you may not have been able to think of.
Timing yourself is important as you want to ensure that your speech isn't too long or too short. If their is a time limit, you want to ensure that your speech remains within the tine limit and doesn't exceed it or go below it by a large amount. As well as this, if you have a time limit, by timing yourself you can also ensure that you have an amount of time as a margin of error in case on the day you have to present your speech your pace varies or you make a mistake.
