Many of the character meet and greets have photopass photographers, but some do not. If there is a place to scan your magic band after a ride, be sure to do that. When we were there in October, there were still some rides that required a scan- I know we scanned at Buzz and Test Track.
My big tip to you to maximize memory maker is to keep your eyes open for photopass photographers and stop when you see them at different locations. I usually do it until DD gets fed up and refuses to take another picture!

You will spot them by their vest. We have some great photos from around world showcase at EPCOT. Just because when you look you don't necessarily see what you think would make a great picture where the photographer is, does not mean the photo won't turn out fantastic. My favorite all time photopass photo of DD is one taken at DL outside Minnie's Breakfast. There is no character in the picture and nothing special in the background, but when the photographer said he would take an additional couple of photos of DD by herself since we had pre- purchased photopass+, we said sure. He took a close up pic of DD with her Duffy bear that totally captures her joy of being at Disney. I love that picture and have it framed at work and at home. Clearly, we ran across a terrific photographer even if the location wasn't special. That brings up another thing which is that all Disney photopass photographers are not created equal. There are some great ones, and there are some not so good ones. We have had blurry pictures, dark pictures, heads cut off, but for each one of those we have had an equal number of terrific photos that we love! For really important icon family pictures like the castle, the Epcot ball, and the AK tree, be sure and get multiple photos from different angles at different times of day. Where the sun is and the angle of the photo can make a huge difference in the picture, as can the skill of the particular photographer. Sometimes we have castle pics that I think are going to be great that are terrible.
Also, photopass photos currently expire 45 days after they are first taken- there is no reason not to look at them as soon as possible. They have added a spot in the
MDE app where you can access your photopass photos. We had some show up within an hour of when they were taken (it can take up to 2 days, but most of ours showed up within 3 or 4 hours of being taken). You can look at your photos every day and that way you can tell if there is something you really wanted where your photos turned out badly and you need to get some in that spot again. Doing that, we also found that some of our really important photos from a magical moment that DD got were not showing up. We have photos the photographer took of her with the characters after, but not the photos he took of her riding with them. We were able to go to the photopass counter before we left MK that day and they found about 90% of the missing photos and added them to our account. We were still missing the first few, but they said they were the first photos of the day taken with his camera so there was probably some sort of issue with it not being quite ready so the first few photos could not be retrieved.