I think the Google sandbox is a myth. New sites can take a while to get anywhere in the SERPS (search engine results pages), but I can usually get them spidered / indexed within a few weeks.
I have keywords at the top spot on Google. I can usually get pages picked up by Google within a week or two and in the serps in about 6 weeks.
To get into Google you need good quality links from PR4 sites.
Now the bad news - to rank highly for website design is going to be tough (especially using white hat SEO). You need everything spot on,
and lots of themed high quality BL's.
Do you use the Google toolbar?
Are you using the h1 tag and is your title tag within this and almost the first thing any spider will find? This can help a lot. The keywords in your title tag should be within the page, looking at your site they are not. Each page should have a different and appropriate title tag related to the keywords on the page, each page is an opportunity to be "found" on Google.
Keyword and description tags look like spam, focus on 1 or 2 keywords or phrases per page, focus tightly on these, for instance the homepage could focus on website design and Glasgow or Scotland.
Submitting to Google is a waste of time they will only pick up a site from a link on a Google indexed / spidered site.
Your internal links back to your homepage should be to the base url -homepage.co.uk not to homepage.co.uk/index, this is then counted as a link to the base URL building pagerank to it and not /index.
I apologise if this is old hat to you and it is a really nice site - nice feel, great navigation.