Unless it's a high traffic area, I prefer a wide grass path.

Path - Photos & Ideas | Houzz

Any style of flagstone and gravel looks great and is an easy DIY.

Depends on the garden, heh. I've got concrete stepping stones I poured in a couple garden areas, moss in another.. beaten a couple, mulched a couple... inside big garden beds tends to be a lot of chop and drop mulching or pine straw in the path.... big garden beds just got mowed around, but the barn cat makes his own path. Out back it's mostly mowing the paths with occasional fixes if there are collapsed spots the tractor can't drive safely over. Those tend to get some reed loomed bundles, sometimes with willow. We got a few straight saplings that need to come out for trail grooming, those are earmarked to build in a log overpath in a particularly bad spot this year.

Since these are going to be garden paths. What kind of gardening? Different gardens can want for different paths. If it's just walking you may want one thing. If you are planning on using something with wheels, or might drag/ low move things a lot- you probably don't want deep mulch, gravel, or large stones that might unevenly stick out. Paths would want to be wide enough to easily accomidate equipment.