Variations are very useful to setup, in this way you will not need to create a new product every time it has small differences as size and colors. You can set a price for all the variations that you desire.
All that you have to do is:
Edit your product and change the “Product Type” from “Simple” to “Variable”
Now scroll down and go to the “Attribute and Variation” section.
1. Choose your Custom Attribute
2. Click on Add Attribute
3. Put the blue check on used for variations
4. select the terms that you desire.
5. click Save Attribute
Now choose Add variation and click Go (click on “add variation” to create as variation you want.)
Now choose from the drop down menu the variation that you want to edit,
Remember to save your settings by clicking on “Save Variations”