I have had a request to please make my original French tip nails that you can find here https://www.curseforge.com/sims4/create-a-sim/french-tip-nails into a default. The simmer wanted to use them in the spa day as a manicure option. I have tested it and it works perfectly. I posted some images to show which manicure style you need to select to get the french tips as your sim's manicure result. 

Important note: You do not require Spa day for this default to work in your game. Spa day is optional if you want to use the manicure option. Happy simming :)