Here are a few things you can change for SEO that will help increase your visibility within search engines.
Your Title Tag is a little long. Needs to be less than 70 characters, its currently 77. Also, unless your business is well known, I suggest using that space for additional keywords. Rewording your title will also help. Something like "Yorkshire Web Design Company. Professional Website Design." I'm not saying use that exactly but play around with it some. Your current title is missing a comma between cheap & professional.
Using Heading Tags don't really help unless you put keywords in them. I think you need to do some keyword research. The keywords you have in your meta tag are not optimized and you don't use commas after any of them. Examples of keywords for your type of website would be "yorkshire website design, website design, web design, website designer."
Image optimization is important, none of your images are optimized. You should have alt text (that include keywords) for all images. Another good image optimization technique is have optimized file names.
"Other Website Design Companies" - Really? One thing you will learn is you don't bash your competition. It makes you look bad and will tarnish your reputation, both personal and professional. This really has nothing to do with SEO but it does show a level of professionalism.
Your really need to look at working on content development. It will help your website appear more relevant in search engine results if you have more content describing your services. Your homepage currently has about 11% text to HTML ratio.
To fix your canonical issues <link rel='canonical' href='http://www.bakerdesigns.co.uk' /> put that in the head of your web page. Each page needs to be the actual URL, so the one above is for your homepage.
You should have a sitemap. After your sitemap is completed, submit it to the major search engines. this enables them to find and index ALL of you web pages faster.
Work on link building. You currently have 3 inbound links.
There are several errors in your CSS/HTML. Check out validator.w3.org to show you the errors.
Questions needed more info to answer -
You said you were having accessibility issues, what issues were you having?
"I am a UK company (so points 1+2 are a Problem!)" What?