Anyone here experienced with mastering?

[grs]

Offer aside, I'd recommend to keep improving your mixing and do less mastering.
I'm at a stage now where I mix everything through one eq and one limiter.
Using the eq and limiter to keep the mix as loud and roughly eq'ed as target.
Then if the main bus eq has a huge boost in the 500hz range then in my mix I need to target instruments that would benefit with a boost in 500hz and give it to them and then take it out of the main bus.