Sometimes, when struggling up a hill, I will spot something, like a mailbox for example, several yards ahead and imagine throwing a lasso around it and pulling myself up to it. Then I'll look ahead for another object and repeat until I get up the hill.
There is one hill I ride fairly often that I have learned shift points on. It begins abruptly, so I work down into 34/28 as soon as I start slowing. I know that once I reach a certain mailbox, I can shift up once. At a certain driveway, I can shift again and then again at a power pole. The road briefly flattens as it passes a side street, and if I'm feeling strong I can shift into the big ring and build enough speed to stay in the 50/24 over the next rise and be really sailing along by the time I top the hill.