I'll keep growing this list as I come across little tibits that help. In the mean time feel free to comment with a quick tip of your own and i'll add it to the list.
Simply select your solid layer and press Shift-CTRL and Y. It will pull up the dialog box so you can change the color and size of the solid.
TIP 1 - How to resize or change the color of a solid after you've already created it.
TIP 2 - Link two text layers content together with expressionsIf you want to link multiple text layers to one in AE so that you change one text layer and it will change the letters in the linked layer(s). This can be really helpful if you have an effect that relies on many layers of text all working together. For instance if you have a typo you need an easy way to change them all at the same time.
HERE IS HOW - Expand the text you want to link to a master text layer until you see text>source text. ALT click the little clock by "source text" to open up the expressions for it.
Now on the layer you want to link the text two expand it as well so that "source text" is visible
Now in the slave text layer use the little pickwhip icon and drag it to where it says "source text" in your master layer. (it won't work if you juts try to place it on text or the text layer)
NOTE: This will not sync the font px size, those would still have to be synced manually.
TIP -3 Scale the selected layer to fit in your composition windowThis is stupid but I always forget the hot keys so I figured i'd post it. To scale the layer to fit in your composition window use these hot keys
Ctrl+Alt+F - Fit All
Ctrl+Alt+Shift+G - Fit Vertical
Ctrl+Alt+Shift+H - Fit Horizontal