Oncemade

A lot of times I end up with a bunch of objects all over in the same layer and it becomes very difficult to select them. That's when “Select by Fill Color” comes in handy.

Choose Unused Color

Choose an unused color and draw your objects.

Select by Fill Color

Select one of the objects and go to Select » Same » Fill Color.

Final Result

Once all objects are selected, change their appearance as desire and you may also want to create a layer for them. Make sure to explore the Select Menu for further options.