Nice ‘checklist’ style post over at RevitKing.  Most things just come back to sensible modelling:
Revit.King’s BIM coordinator/ Revit Blog: Optimal performance for Revit!!!

One of the tips:
Create a family component instead of in-place families when possible, especially for repetitive components. Each in-place family has separate type attributes that Revit has to reference.

To implement this on an existing model, you could convert some of the in-place families to Component families using this method.

Do you have some awesome in-place families that you would like to convert to normal Component families, so that you can load them into other projects?

Here’s how:

  1. Open the Project containing the In-Place family
  2. Edit the In-Place family
  3. Select all of the elements in the family
  4. Group all of these elements using the Create Group tool.  Give the Group a name.
  5. Select the Group
  6. Do not Finish Editing the In-Place family yet!
  7. Go to the ‘R’ button (Application Menu) – Save As – Library – Group
  8. You will notice that the filetype is RFA!
  9. Save the Group somewhere.
  10. You Component Family IS the file that you just saved.

 I’m sure there are limitation to this method, but I think it is very cool.

Here is a quick video:

Credit for this tip – KarelCAD support document