How do you address your direct mail?

I normally hand write the addresses on the envelopes but it's starting too take too much time and I need to scale up.

I'm thinking either printing the addresses off on sheets of stickers and sticking them on, or buying envelopes with a clear window. I've seen businesses do both.

What do you guys do?

I have used mailing labels for post cards, it is DEFINITELY faster than hand writing them yourself. On my current mailers I am hand writing them. This is to try to make it look less like their in particular mail piece came from a batch. If you don't care about making it looking personal I definitely would recommend using mailing labels. You can make them with Open Office.

Hand writing would make it look personal and it might make them at least read it. But clear window envelopes would seem to look more professional.

Handwritten might appeal more, but a typo can ruin everything.
Would love to heard more idea's on this