Practice, practice, practice, and then practice some more!
There are so many great tools out there to use for practice. Use fake skins to get down brow shaping, holding the blade and stroke placement. While practicing on these fake skins don't forget to get in the habit of always dipping your blade into pigment. Also, use this as an opportunity to practice stretching. Great stretching techniques help to complete a beautiful long lasting brow.
The Tina Davies Angie practice pads are great to practice strokes on. The Angie practice pad allows for you to see if your hair strokes are even, if your blade was being held properly or did you make your one stroke into two by not keeping a steady hand. The Angie pad allows the technician to see every little detail in their stroke as it is not covered by pigment.
Use your imagination and be creative with microblading. It isn't all up to the ruler to achieve perfect brows. Keep in mind what fits the clients face, what the client is looking for and of course, your professional input to create a beautiful look that you are both happy with.
You are new to this and learning a new skill doesn't always come easy. Watch videos, read blogs get as much information as you can. Always keep in mind learning a new skill doesn't just happen overnight. Be patient with yourself, be confident with your work and keep practicing.