Preparing your brush!
When you receive your acrylic brushes for the first time make sure you use your fingers to work the gum out of it. Press it gently with your fingers to break the seal, then lightly fluff it with your fingers. You will see some white dust coming out of it, you need to continue until there is no more dust. Then work it into monomer and wiping it on a paper towel to get rid of the dust completely. Do not dip it into polymer/acrylic powder until all of this gum has disappeared, if you do then you will clog the brush and it will be ruined.
With gel brushes do the same as above, except instead of monomer use IPA to get rid of the residue.
If you don't do this then your brush will clog up and become damaged.