Create functions - When coding autonomous, declare functions that you will use frequently. (Examples --> moving forward/backward, raising/lowering arm, open/close claw, etc.) This makes the programming process quicker and easier, as otherwise it would take multiple lines of code for only one simple task.
Keep testing the program - As you code autonomous, test the program step-by-step. This makes it easier to find mistakes and correct them.
Remember the positioning - Autonomous can be incredibly finicky, and positioning your robot even slightly off from its normal position can cause it to not work. Make sure to remember where you position your robot when you code, and always put it in the right spot. Use the lines and holes on the field to help you stay exact (Vex IQ).
Changes to the robot affect autonomous - If you make any changes to your robot, make sure to revisit the autonomous and make any necessary changes. Autonomous is incredibly finicky, and slight changes on your robot can completely throw it off! Try not to start autonomous until your robot is complete and your team is happy with it.
Document - Make sure to document your process in your engineering notebook when coding the autonomous. Document any issues that came up, how you solved them, or simply what you did when programming. Make sure to write this in your notebook as you go along, as you will likely not remember everything in the future, and it will also save you lots of stress. For more notebook tips, click here.
Use your resources - If you're having trouble, you can almost always find help online. Online forums for Vex can often be very helpful. The RobotC help page is another good resource. Don't be scared to ask your teammates for help if you need to. After all, robotics is a team effort!
Organize your code - Use comments in your code to label different sections of your code. It will help you code faster, without having to search for the specific section of code you want to edit every time.
For links to all the different programs you can use to code in VEX, click here.