Venerable Ru Jun (如俊法師) discusses in one of his discourses on doing repentance - the importance of doing dedication in a correct manner so that we do not waste the merits that we have just obtained.
In it, he mentioned 3 areas we should dedicate the merits for:
I also picked up the point that when doing dedication of merits, we can dedicate the past, present and future merits of all sentient beings (and this will include the Buddhas and Bodhisattvas).