I spend a lot of my time creating User Actors in Isadora. User Actors are possibly the most powerful internal building block that Isadora offers. They allow you to create a library or code/patch objects, that you can save externally, but the most powerful feature is probably that fact that multiple instances of a User Actor can be updated by simply updating one in your patch and allowing Isadora to update the rest for you when you close the User Actor.
My favorite way to optimize a large patch it to use a User Actor specific actor, 'User Actor On/Off', this actor works like bypass on most every other actor, in that it will allow you to shut off the processing of a User Actor, but unlike bypass in that inputs do not make it thru to the outputs. This means when you turn off a User Actor with the 'User Actor On/Off' actor that it is dead, and a dead end to all inputs.
This is an amazing way to save CPU cycles when you are switching between features (used HEAVILY in Syst3m to allow video FX and ALL other features).