I'm posting stuff I've learned from making symbols here I'll update this every now and then for now here's this.     1 -  To make your symbols a bit "sharper/cleaner" you can put "background sqaures" on the edge of your symbol to make the edges sharper instead of having "rounded corners" and weird stretchyness here's how and what it looks like,   Notice how the bottom and top of the "pale pink square" has rounded corners and a soft edge instead of a sharp square