From Longman Dictionary of Contemporary Englishget/keep your eye inget/keep your eye inBritish English informalDS to practise or to continue practising an activity so that you become good at it → eye
Examples from the Corpus
get/keep your eye in• Even after his second wife left him in 1991, Thurmond has kept his eye in practice.• It all helps to get your eye in and is far better than trying to rely on memory. 