2k around a 'honey pot', such as Crewe or the Wrekin, demands eyes everywhere, so I prefer to be at 3k+ whenever possible, especially in those areas. It also gives you a bit more time to sort things out if the donk gives up.... And as high as possible over water! Btw - some allowance needs to be made for QNH - regional/local above airfields or in the local CTA - make sure you've set the correct one for where you are - and has everyone else?