This is my mother's recipe for pudding; it's the one she always used for traditional banana pudding with vanilla wafers and sliced bananas. It's also the one she used to make my father's favorite chocolate pie topped with meringue. You can add other things to it if you want - say, a mashed banana to make a smooth banana pudding. I've not used other fruits so cannot help with suitable ones nor amounts.
1/2 cup sugar (original calls for 3/4 cup)
3 tblsp flour
2 cups milk
3 egg yolks
1 good pat of butter
For chocolate add 1/4 cup cocoa.
Put the sugar and flour in a medium saucepan (and cocoa if making chocolate), and stir this to blend well. Get all the lumps out. Add the two cups milk and stir well. Heat this slowly over medium heat, stirring frequently. While milk is heating, whisk the three egg yolks until they're creamy.
When the milk is just past warm, temper the eggs with it. Add the tempered eggs back to the pan. To temper the eggs, slowly add hot milk bit by bit stirring to keep from cooking the eggs. Any amount from 1/4 to 1/2 cup milk will do it.
Continue heating and stirring until the mixture thickens. Add butter and stir in. At this time you can put into individual pudding dishes, make traditional banana pudding, put in one container, or pour into a pie shell.
Here is a pic of the mixture coating a spoon at the point where I take it off the heat.