you must concentrate your effort on the different character which construct every chinese synonym with the other character when you meet this situation again.(of cause, it can't include all situations. it just is an advice. )
for examples.
发票 & 票据:the different character between them is 发 and 据
本事 & 本领 & 本钱 & 资本:the different character between them is 事、领、钱、资;
some chinese words are often combined by two character which has almost similar meaning. so we call chinese is a language whose morpheme is very prominent!
So
专注和集中的区别就是专、注和集、中的区别。
专:specialise in
注:inject
集:gather
中:centre
try to feel what are they different. i hope these can help you