This advice will be most applicable to Heathenry since that is my practice, but this can be applied as well to other traditions that honour land spirits.
Physical offerings to land spirits are of course traditional and good, but are not the only way to honour them. There are other ways to venerate them while also spending more time in nature. Note that where you live (city, town, village, etc) will determine how much you are able to do.

Picking up trash: simple and applicable to essentially any location. Can be low-effort.
Planting native plants: wonderful act to help boost local biodiversity and help species. Requires research and often money.
Gardening: in general taking care of plants is great practice for many reasons and is a great way to grow more respect for the land.
Prayer: the easiest action to do, just a simple acknowledgement of their existence and thanks for what they do can go a long way.

If you have any other ideas or practices, be sure to add to this list in the comments!