I hate the word summoning, it has such a negative definition.
Summon: To order to appear.
I could never get away with summoning my loved ones when they were alive, my chances now that they are passed have greatly diminished.

And I wouldn't really want to command them to do anything even if I could.
I much prefer the word invite.
Even with my magic, when I am casting spells and calling the corners it is only ever an invitation for the powers to attend, never a summons.
I have found through my experience that it is always better to be polite when they have something you want. You're more likely to get what you ask for that way.
And the only reason you would summon anything would be to ask it for something wouldn't it?
Good manners in any situation help make things turn out the way you want them.