I had a difficult time defining my pricing when I started freelancing.

Then I got hired on the client-side and could compare agencies fees. That gave me a good idea about how much everyone is pricing themselves (anywhere from 400€ to 800€/day in marketing, Belgium, 2018.) I took that as a base and decreased my hourly rate by time on the project (1h, 1 day, 1 week, 1 month, 1 year.)

Now I have more ideas on how I could change my pricing (freelancer, small or medium companies, corporates, non-profit, yearly revenue, the importance of the project, etc.) Little by little, I will try and test them out.