All coordination methods follow some common principles, which are listed in the general principles article.
A controller acting a delivery position gives only initial IFR departure clearance.
This position is present only in a few numbers of airfields and can be cumulated with GND controller. This position is used only on the busiest airfields with much traffic.
This coordination is not needed when DEL position is merged with GND position.
DEL controller is not close to APP controller but, in particular cases, he must negotiate clearance with him, since the APP controller is responsible of departure routes.
This coordination is not needed when DEL position is merged with APP position. Be aware that the en-route (CTR) controller is in charge of APP position if this position is not opened.