Simple items at home to create nice effects

I like taking pictures and also like creating interesting effects with no digital alterations. The challenge is making it with stuff you may have at home. 
Look at these 3 photos of a simple object, can you guess what I used yo get those effects?

Let see if you guessed:

1. Tissue paper with an opening

2. Ruler for drawing ovals and squares 

3. Ruler used for making sewing patterns

Here a pic of the 3.

Leave a comment if you try any of this or if you have tried others please share, I would love to see :).