Should I do a percentage off? A dollar amount? Should I cap it somewhere? What works for you guys? How do I not get taken advantage of it that makes sense haha

I do custom cakes, so I want the promo to only work on cakes over $100, which is very common for custom cakes. I make about 8-10 cakes a week.

This is what I'm thinking so far. Is it going to back fire on me? Please be honest.

10% off orders over $100 for first 5 referrals.

15% off orders over $100 for the next 5 referrals (so between 5-10 referrals).

20% off orders over $100 for the next 5 referrals after that (so between 10-15 referrals).

and then lastly 25% off orders over $100 for the next 5 referrals after that (so between 15-20 referrals).

I'm thinking of not allowing it on wedding cakes. Most of my business it word of mouth.