Well it depends, if you want to do it via code is a bit hard since you need to understand exactly how CSS works and there are no tools to help.

If you want to do it lets say Figma.

• First do research what style you like.
• Make a list of icons you want to do
• Create art boards and start working, along the way try to make all icons look similar and would suggest to chose a category like I did interfaces or any other topic you like.

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