Tips for making roomspray with fragrance oil and perfumers alcohol

Hi there, I am testing roomsprays. For this I am testing with perfumers alcohol with fragrance oil. At a lot of suppliers they advise to add 5% fragrance in with 95% perfumers alcohol. I have tested this at home but I find the roomspray not good at all. after 15 min the scent is gone. I really want to make a high quality scent / high room spray. Is it also possible to do like 15% fragrance oil or 20% fragrance most of the IFRA51 docs for my fragrance oil allows this. and the rest with perfumers alcohol? I really want to start a company in this. but not sure if this is possible for a roomspray at home. does people have tips for me? and does other companies also add this kind of % to their formulas?

tips are welcome.
thanks a lot! I am selling in the EU btw.