There are several tricks, depending on what is available at your school.
HOW TO DO BETTER IN LAB
Read the lab procedure before coming to lab! It helps you be prepared so that you know what not to do.
Label all your bottles, flasks, etc. with some tape if available. That ensures that you don't mix the wrong substance with something else, and get the wrong observation down.
If you feel like you messed up a bit, ask your teacher's assistant (TA) to check, and have them give their input on whether you did it right, if you're unsure.
Leave your glassware far enough away from the edge of your lab station. That helps you to not bump it and spill anything.
HOW TO IMPROVE ACCURACY/PRECISION OF MEASUREMENTS
You can use a white piece of paper and wrap it around behind a burette, pipette, graduated cylinder, etc. to read the index mark more clearly. If you use a dark reagent, try to find a burette with light markings.
Try to practice doing more precise motions. Practice squeezing DI water bottles more lightly to dispense drop by drop if needed, tilt glassware slowly to pour, use a glass rod to force liquids to travel along them into other glassware, spin the stopcock on a burette
A static gun allows you to get rid of the static electricity around a scale, which stops it from drifting. Scale measurements can drift when you bring blue nitrile gloves near them, which makes it hard to settle on a number.