One thing I would have appreciated as a home-brew DM/GM would have been something to help outline how to create monsters by level or by type. Maybe just one more Appendix to sum it all up in one spot.
There are some tools that help in monster creation in the DMG, like the X.P. Value of Monsters table on pg. 85. If you use the column headings in Appendix E you are well on your way to having a basic foundation of what info you need to create for new monsters.
I am thinking of creating a Create A Monster By Level and Type guide for myself and of course, I will share it freely. The reason I want something like this is that for every monster I create, if I take any longish amount of time off in between monster creations, I have to try to remember all that I did last time and how I did it.
I start with Type or Class of Monsters. Deity, Dragon, Giant, Undead, Demon, and then general types such as Humanoid, Fish, Animal, Bird, etc...
Now that I have the type I move on to level, for me, this is trickier. If I am planning a specific adventure and I want something new to challenge the party at a specific point, I want to make sure they are going to be such a proper challenge and level helps me to do that.
For example, a 1st level demon does not have the same powers and abilities that a 5th level Demon has. If I want a deity, there are minor deities and there are major deities thus there are differences there as well.What is the difference? How many HD does a Major Deity tend to have as opposed to a minor one? This is where my guide will come in. How many spells does an Arch Duke of Hell get vs a 5th level devil?
These are questions that need answers and they have answers one just needs to look through the MM1 to find them.
I'll put this together because I'm bored enough to do it and because I want it.