This is how I usually do what I call my "perfect start" or "super start". Adding some APM to it. Another one of my start, a little bit different.
As soon as the game starts, select your base and build a worker with it's hotkey. Right after, hold Shift and select your 4 workers and send them to a close mineral. In slow motion, 15% of actual real speed.
Still holding Shift, left click on a worker to remove it from the group. Send the rest of the group to another mineral with a right click. Repeat this step 3 times to send the rest of the group to different minerals. Do it as fast as you can!
Extra Tip #1: You can select your whole group by holding CTRL and clicking on one of your worker instead of selecting them. Stop holding CTRL right after it.
Extra Tip #2: Set your base's rally point close to the next mineral you want your new worker to go to gain some milliseconds.
Extra Tip #3: Assign your base to a group with CTRL+Number of your choice, so you can make workers quicker than selecting it every time and without losing focus.
Let's see that a last time. Sending all the workers quickly on different minerals.
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