Network, network and network. Build a decent portfolio of work - and you won't have too much trouble.
My company is a technical development agency for E-commerce. We only handle development and work with other partners for peripheral works (design/ux/seo/sem etc.). So we're always on the lookout for reliable, decent web designers.
In the web world, if you've got a firm grasp of UX, you won't go wrong entering the e-commerce design world. I could maybe send some briefs your way and you could come up with some designs; if its up to par and you show a good understanding of space, colour and UX, then we can use and refer clients to you in the future.
HTH
