First put down your phone and go to find a Scissor and a plastic card (not your credit card) and then come back.
The Plastic Card is the perfect friend when you want to quickly create some Texture in your Watercolor. And one Plastic Card has a lot of opportunities for different marks. I cut this card up in a few pieces.
Think about getting a few sizes of flat surfaces, a round edge and a pointy one.
See if you can find a small box to keep them safe. I recommend a small jewelery trinket or something similiar. Then you always have you tools close when you need it. I just tested the different bits and got a wide range of pretty cool marks in the watercolor. Just imagine using these for trees, rocks, bricks and even hair or flower stems. There are so many ways to use it!
And remember when you are using the plastic card. Wait for the wash to be shiny instead of soaking wet and then press pretty hard on the paper. Just be careful not to ruin the paper. If this is your first time trying out this technique I would do a couple of experiments before going into your precious art.
If you feel like exploring this even further I have a super short video on Youtube showing 3 techniques.
And then I have an entire class dedicated to creating texture with Plastic Cards(!)