We re-use what we have and add to it. This is our 3rd Christmas in a house, and the first year we got icicle lights for the top of the house and garland for the porch. Last year we added lights to the garland. I literally just got back from Home Depot for our new thing this year — 2 light-up hanging stars to add between the columns on our front porch. Next year I’m hoping we get our act together enough to install a hook for a big light-up wreath.
We use the same ornaments every year but add to the collection when we travel. I like the familiarity of using the same things year after year. It’s also nice to already have all the hardware in place for hanging lights — we hid hooks under the eaves for the icicle lights, so putting them back up again is super easy now.