I have very good SERP at Google.com, but for Google.co.uk I cannot find my site on first 10 pages. How can I improve the situation?
In your webmaster tools you may want to change your target audience under settings, but this may effect your google.com rankings. If you want to rank well in the UK your website really needs to be hosted in the UK and you need a .co.uk domain name (this will help a lot), you may want to set up a new site and target the UK and keep your other site targeting google.com
If I set up a new domain that will be a new domain; therefore new web site that will needs separate link-building, content and optimization.
Yeah if you set up new domain, you will have to start from scratch again on every aspect of SEO. If your prime target is only UK and i think you can follow what enchancSEO suggested.
we just did this a while (5 months) ago, switched to UK inside WMT. at the time we were nowhere in the UK on most of the same terms as in the US. the site is a .com, hosted in US, and is now ridiculously strong in the UK, way over and above comparative performance in the US, and havent seen any drops on US to speak of, in fact its mostly continued rising slightly over that period there too. couldnt be happier with the WMT UK settings