I have been a fulltime freelancer for about a year and a half. My first year was very very hard in terms of consistent work. It is only now ramping up a bit better with better rates and a bit more consistency in work. I went from 100 dollar gigs to 1000 dollar gigs in that time, but the majority are in the 200-500 range.
BadWoolf gave you some solid advice. The only thing I will disagree with is the statement that if you don't hear back you should assume your work isn't up to scratch or you hit up the wrong person. People are often just too busy to respond to everyone especially at large companies, even if your work has interested them. Sometimes it takes months for these things to filter through to actually getting looked at. I got no response at all when I sent my stuff to FFG. 3 months later I got a solicitation email out of the blue.
Your work is pretty solid technically and you have a pretty interesting style which is fairly unique, so you definitely have that going for you.
In terms of your folio, I can see your work being used in children's books, perhaps in editorial work as well, but I would suggest you need to show more of what you can do that might be tailored directly to those markets. Your folio is a little light in that respect. For example there is that grayscale portrait which technically is great but arguably less viable from a client perspective. I like your design work and cool pencil sketches but I wanted to see more finished illustrations, and also more complete scenes that show environment and characters interacting with them. Your stuff has no environments at all, and so much illustrative work will require this as well to some degree, except maybe for pure editorial or straight up character design work which at the moment I don't get from your folio. You have some great stuff showing an affinity for design in your sketchbook do and show more of it if that's what you want to do! The figure study, while cool, probably won't get you any jobs!
The absolutely vital thing besides constantly adding new and better pieces to your folio and taking out the weak links, is marketing. You mentioned sending to a "few" agencies. Won't cut it unfortunately if you are trying to get consistent work. You have to send to hundreds...and keep sending consistently before you start to get bites.
Do your research and target your work to publications or studios/companies that are aligned with what you can do, exactly as BadWoolf said. Also check out all the sites out there that post illustration jobs; artstation has a job section, conceptart.org, even dA forums occasionally posts jobs with decent rates amongst the 20 dollar gigs. I wouldn't bother with the horrible sites like elance or freelancer which use a bidding system. Skip those.
Compile a list of potential clients and when you contacted them last. Update this at every contact point so you can go back and see who you might contact again after some time. Make a routine of it. Do an hour+ of this every day. I do a research run, and when I find a suitable target, I immediately make a draft email with appropriate links and save it. When I am done with my hunt, I go to my list of drafts, finalise them and send right away. If I don't get to all of them, they are waiting in my drafts folder ready to go the next chance I get.
While you might have to take some low-paying jobs I find it helpful to have at least a minimum value which you will not go below no matter what. Don't undersell from the get go even with small indie clients. You can always negotiate down a bit, but you can't negotiate up. I used to have a $100 minimum for any piece. It is now $200. If clients don't like it (yes INCLUDING your friends), I send them on their way politely, but keep the door open for if they choose to come back. If they are serious about your work, they will go away "rearrange" some stuff and come back with something you can work with.
Being a professional artist has a lot to do with attitude and how you present yourself. If you don't value your own work and stand by it, don't expect anybody else to.
Understand contracts and licencing. WELL. ArtPact has great boilerplate templates, which I use to this day.
Post your work in multiple places. Social media (twitter, facebook, instagram, tumblr etc) Create and maintain galleries in all the big illustration websites (ArtStation, dA, cgSociety, DrawCrowd etc). The more you get stuff onto the web, the more it will spread and the chances of it getting picked up by potential clients grows organically. Submit work to imagineFX every so often, eventually you will get feature. They are always on the hunt for up and comers to feature.
Enter contests and challenges with decent exposure. Even just entering things and not winning gets your work out there and visible. Enter the illustrators of the future contest every quarter.
http://www.writersofthefuture.com/enter-...r-contest/ I won last year, and got flown to LA all flights and accommodation paid for a week! That's 4 chances a year for a pretty awesome prize, and the pool of contestants is relatively small compared to other contests.
Consider doing some fanart and posting it on the forums that are often run for these IPs. Also post on imgur, reddit etc. It might not be your thing, but doing work on well known IPs has a much bigger immediate audience reach than personal work.
You just have to keep at it and not get discouraged. At a certain point, doing all these things will land you better gigs. Good luck!
