Being organized and clean when you are a MUA can be a little challenging, specially when you are working almost everyday and with multiple clients, but it is very important to be organized and to master hygiene if you want to be successful and an artist your clients can trust.
Some tips I can give you to have in consideration in order to be organized and clean are:
Try to have a least 2 or 3 sets of brushes OR doubles of your favorite brushes to apply makeup. The reason why is, just in case you don't have the time to clean up your brushes for your next job or client, you already have clean one to use.
Be disciplined on maintaining your brushes clean and disinfected. EVERY TIME I finish a job I sit down and clean all my brushes. That's something I pushed myself to do because it's very time consuming, piling them up and then cleaning them all at once. Also, I wash all my brushes every week with shampoo to maintaining them looking like new and fresh.
If you are working with different people at once, make sure you separate the brushes of each person and have your brush cleaner ready to clean brushes if you have to re-use them.
Have disposables, like mascara wands, beauty sponges, lip applicators, etc.; that helps a lot when working with more than 2 people at a time because those you can just throw away and be done!
Clean all your makeup pots, like foundation bottles, powder pots, eyeshadow palettes, etc.; take a makeup wipe and wipe them all, you don't want your client to see your kit all messy, that talks about you and your work ethics.
Lastly, have alcohol or Clorox wipes and hand sanitizer always in your kit. It's important to clean your station before and after you work; also, use hand sanitizer to clean your hands before starting with a new client.
These are my most important tips I've followed to make sure I have a good hygiene and organization in my makeup practice, hope this can also help you to be a better artist.