Sticky Slime: This is a classic problem, often caused by too much activator like borax solution or contact lens solution. The good news is there are a few ways to combat stickiness. Start by adding a tiny bit of water, a teaspoon at a time, and kneading it into your slime. Be patient, as it can take a while for the water to be fully absorbed. If adding water does not do the trick, you can try adding a small amount of cornstarch or flour, one tablespoon at a time. Knead it in thoroughly, and stop adding once the stickiness subsides. Cornstarch and flour will absorb some of the activator, making your slime less sticky. As a last resort, you can add a little bit of shaving cream. Shaving cream adds volume and can help reduce stickiness, but be aware that it can also make your slime slightly less stretchy. Stiff or Rubbery
Slime: If your slime feels stiff or rubbery, it likely needs more activator. Add a few drops of your activator solution at a time, kneading it in well after each addition. It is important to go slow here, because adding too much activator can take your slime from stiff to clumpy in a flash.
Clumpy Slime: Over-activated slime often ends up clumpy and difficult to work with. There are a few ways to try and salvage clumpy slime. If the clumps are small, you can try kneading the slime vigorously for several minutes. This can sometimes help to distribute the activator more evenly and break up the clumps. If the clumps are stubborn, you can add a tiny amount of water, a teaspoon at a time, kneading it in well after each addition. This can help to loosen up the slime and make it less clumpy. In extreme cases, you might be able to revive clumpy slime by adding a small amount of clear glue, a tablespoon at a time. However, this can be tricky, and it is important to stop adding glue once the clumps start to break up, or you risk making your slime too stiff.
Soupy or Runny Slime: If your slime is too runny or soupy, it likely needs a thickening agent. There are a few household options you can try. Add a small amount of cornstarch or flour, one tablespoon at a time, kneading it in thoroughly after each addition. These will absorb excess moisture and help to thicken your slime. Another option is to add a small amount of shaving cream. Shaving cream will add volume and thicken in your slime shop, but keep in mind that it can also make it slightly less stretchy.
Deflated or Flat Slime: Over time, all slime tends to lose its air and become a bit flat. This is especially true for fluffy slimes. Luckily, there is a simple fix! Add a little bit of shaving cream to your slime and knead it in well. Shaving cream will add volume and make your slime fluffy again.