The authors of "Converastion Gambits" have taken a very "lexical phrase" approach to conversation skills. Each unit is very simple, and gives a range of expressions for students to learn and memorise as lexical phrases. The theory is that native speakers have huge stockpiles of such "chunks" that we draw on.
The skills covered include responding with sympathy, interrupting, expressing opinions, disagreeing, back channelling, and a huge range more. Each unit has a simple practice exercise, though this will need to be supplemented with other exercises for more extensive usage.
I have found that students enjoy it and love the input. They also love using the new phrases. It is a great resource that works for a whole range of levels.