Some points to bear in mind.
1.Watch the length. Better to leave people wishing for more rather than for less!
2.Humour is always tricky; never more so than at a funeral. Aim to laugh with, not at.
3.The eulogy is about the deceased, not you, so keep your stuff to yourself.
4.People who are listening to you will be upset in various degrees.That’s fine. If what you say upsets them further, that's no reason not to say it, if you judge - and it is very much a matter of judgement - it will deepen the integrity of the occasion.
5.Try to identify and then stick with a well defined theme. That will make people follow you more easily.
6.A eulogy means literally “a good word.” Traditionally, a eulogy tells us what a great person the deceased was. Fine. But s/he was also a human being. Without labouring it, you will be more credible if you paint a recognisable picture, rather than a gilded saint.
7.You might well want to talk to people who knew the deceased better than you did - eg a partner or offspring. You may well learn things that you did not know and therefore the vast majority of your audience won’t know. It is often those little revelations which people appreciate. “He was a member of the Magic Circle. Well! I never knew that.”
8.Unless you are an experienced public speaker, you will be nervous. Nerves tend to make us make two mistakes: we talk too fast and we drop our voices. The result is that no one hears what we have said!
9.Take particular care of your first sentence and your last. Thr first should grab people's attention; the last should give people something to take away with them.
10. It is always worth writing your speech out in full, and to have it with you. But you need not read it when you come to deliver it.
Delivery. 1.It is a privilege to be asked to deliver a eulogy. Let your demeanor show you realise that.
2.Remember that you are doing this as a tribute to the deceased.Your delivery needs to be worthy of him/her.
3.Make sure that you know at what stage of the ceremony your eulogy comes. And from what point you are to deliver it.
4.There will almost certainly be some kind of sound system. Check before the funeral that you know how to work it and what setting(volume, pitch) are best for you.
5.You will have the full text of your eulogy with you, but you will communicate better with your audience if you do not read it.Glance down at it from time to time if you need to, but try to memorise it . You probably won’t get it word perfect: that does not matter a toot. What does matter is that people listen - and are put in touch with a real person they knew and liked.
6.One good story is worth more than a mass of pious platitudes. Two good stories are gold dust.