The best thing you can do is continue working in the same style or theme as the project you just finished. Sometimes a work of art stands really well on it's own, but sometimes building a series based on the same technique or idea can really up the impact of your work.
Working in your Art Journal is a great way to practice creating art without worrying too much about the finished product. You can practice with different materials and techniques, or just sketch. Anything you do will help build art-making skills, so go for it!
If you finish your project and are ready for something new (other than working in your Art Journal), feel free to start something else. You are welcome to come up with your own ideas or choose something from one of the prompts to fill your time.
Materials: 80# paper or watercolor paper, watercolor paints, paintbrush, water cup, sharpie
Use watercolor to paint splotches across a piece of paper
With a sharpie, outline the splotches where each color ends
Add a pattern or design around the outside of the watercolor. Keep in mind the principles of pattern, rhythm, contrast, and movement as you create your design.
Materials: drawing paper, ruler, pen or pencil
Divide your page into at least 12 sections
Practice different types of mark making in each section. You can use the same types of marks as the example or you can make up your own.
Label the sections
Materials: drawing paper, sharpie or pencil
Divide the page into random sections
Fill each section with a different zentangle design
Here is a great resource for how to draw zentangle patterns, but at their root they are just very repetitive patterns.
Materials: pencil, thin sharpie, coloring supplies
Trace your hand in pencil on the middle of your page
Trace in thin Sharpie
Use a thin sharpie to divide the page into sections and add detailed designs to each section
Color in your designs, leaving either the hand or the background uncolored.
Materials: drawing paper, magazine, scissors, glue stick, pencil and eraser, other drawing supplies
Find an image in a magazine that you like and cut it out.
Cut the image in half and glue it into your sketch journal
Using a pencil, do your best to recreate the other half of the image, or create something totally new for the other half.