Two approaches for making guilds. One starts from grassland, the other from more intensely used part of the garden.

The guild around a cherry tree in the first image evolved over the past few years by changing the mowing pattern and adding haphazard mulch of various materials. It consists of perennial grass, nettles (good biostimulator for the soil), Rumex (deep taproot), self seeded Robinia trees and clover for fixing nitrogen. The only thing i did myself was dig a swale , plant some jerusalem artichokes, put in few piles of mulch, some logs and stop mowing frequently.

The freshly planted guild around a young apple tree in the second image consists of comfrey, Artemisia abrotanum, Laevisticum, Lavandula, Chives, Narcis and Tropaeolum and white clover as ground cover. Under the dripline of the tree ( when mature) I've planted a few ribes shrubs. In the background Elderberry and nettles (both good biostimulators). For mulch I used Soja straw and elderberry woodchips (the latter decomposes very quick, good boost for soil life).

The third image shows companionplanting around a young peach tree.