Man I think making a portfolio in the first place is my second problem. My first is that I don't know what exactly I'm selling. I rarely do fanart although I should, and I don't have a niche that people are really interested in. Would be cool to find that.
Do you watch anime and manga often or do you just like the style? Not really sure.
Yeah, I realised it's not just about doing fan-art it's how you present your work that will divide you from the rest, otherwise it's down to plain ol' skill and that takes the longest to nurture and train.
Think outside the box
I used to watch anime and read manga all the time, I'm mostly a seinen fan now, though for the shonen HunterxHunter is my fave 'shonenesque' shonen. Death Note is all time fave shonen (after watching bakuman I realised just how well Death note was done).
Seinen titles include zankyou no terror, gantz, elfen lied, ergo proxy, steins gate, parasyte, serial experiments; lain, inuyashiki etc etc
Otherwise sunkenrock, genkiryuchi, Gantz, holyland, suicide island (the last two in particular) are amongst my fave manga titles.
My fave story of all time is Monster. Head and shoulders above everything else.
So yeah I'm definitely a fan, but since bleeding into comics I've found myself much more drawn towards the western works again