MakeupbyMelina wrote:
...looking to work with models and photographers to build my portfolio...

Melina, please consider using Mayhem's Casting and Availability Notices Function to find colleagues to collaborate with...

MakeupbyMelina wrote:
...I am also keen on getting advice on how to be a successful freelancer mua...

You might consider posting this query in the Hair, Makeup & Styling Forum in as this would be the most appropriate and germane Mayhem Forum to address this.

That said, every market is different... Here across the pond in Washington DC Bridal makeup gigs are the highest paying albeit the competition is rather keen... My revenue in makeup artistry comes from both Bridal and commercial assignments for Corporate Video. The corporate work is via an advertising agency in NYC. 

You would be wise to canvass the successful commercial makeup artist in Birmingham, England as to their client mix. Once again every market is different and markets vary depending on the time of year i.e. in Washington DC bridal is in extreme demand during May, June and July the falls off considerably as winter approaches. 

btw, here is my Mayhem Makeup Artist Profile

Hope this helps or is at least food for thought...
I wish you well on your journey Melina