Two Xcode plugins I didn't know I needed

Mini Xcode

GitHub

Let's you select scheme and device with a simple (Ctrl + 7 Ctrl + 8) shortcut. It also lets me size every window the way I'd like. No restrictions based on the toolbar.

DerivedData Exterminator

GitHub

Puts a button up on the toolbar, and works well with Mini Xcode: Select Derived Data Exterminator in Title Bar in the View menu.

Love em.