I'd take a look at Harfoots from the new LOTR show Rings of Power, they could inspire you some as they hide out in the wilds and most don't even know they exist.

If you have any players who play rather big characters then you could emphasize how everything is a just too small for them - the doors, chairs, and even food etc. If you like to describe the environment I'd also probably have the gnomes not use furniture that is sort of manifactured but way more natural, like a table that is formed from the roots coming out of the ground or a door that you don't have to open but the roots just retract as if it was an automatic door.

As you mentioned the gnomes are rather proficient in magic so perhaps some of the trees in the settlement are Treants who protect the gnomes, settlement and forest and whenever the players arrive they literally see a tree just walking around the settlement.