Google.com & Google.co.uk SEO?

I was wondering, how do you actually get ranked using SEO on a specific domain extension in Google? For example, there's an amazing keyword that gets 20K searches per month in Google.com and about 8K searches per month in Google.co.uk but the competition on Google.com is very high whereas the competition in Google.co.uk is very low. So I was wondering how do you use SEO in order to rank for a specific keyword in a specific domain extension?

1: get local backlinks
2: make sure you have some indicators that you are targeting a local country (phone number, contact information)
3: set google webmasters to target the specific country
4: Mainly advertise on local websites
5: Get local hosting (not necessary, but can help)

(I am pretty sure of the above based on experience with multiple country targetting, the country I live in is just too small )

That should do it.