The Inktense works very similar to watercolor pencils, they're water soluble. The big difference is that when wet, they turn into ink! Unlike normal watercolors/watercolor pencils, once completely dry, water cannot reactivate it. You cannot rework the colors, but you can add multiple layers over the dry ones and make the picture more rich in color and make certain aspects pop more.
These pencils can either be used wet or dry. Dry, they tend to have a deep richness to them and become translucent when wet. They do dry fast though, so it can be tricky trying to avoid those "blooms"(You can sort of see it in my iris blue on my color chart. I added a bit too much water...oops). An aqua brush(paint brush you can fill with water) works really well with these. They can be wetted on paper, or if you want to use a more painterly approach you can take a brush and wipe it on the lead of the pencil to collect the pigment. Whatever works for you.
Overall, I really love these. I love the way the respond to water (more so than my watercolor pencil set I owe). Perhaps with time I by their other colors separately. I brought them over to my friend's house and we were both messing around with them, having a blast.
Here are a couple paintings I created with them;
Sunset:
Peaceful Valley:
'Sunset' on 3.5 in x 5 in Strathmore Visual Journal watercolor paper
'Peaceful Valley' on 9x12 in Canson XL watercolor paper
Whether you're a hobbyist, serious, just like messing around, give them a shot.