I really only played Green, with some shy attempts at other colours that didn't end too well (was fun, just not effective).
Seedlings are good, so are tiki caretakers and Bloomsprites for early game farming, which you should be doing since green is better the longer the game goes. Wood elementals are auto includes. Tiki totem and Overgrown tower are good if you can fit them in your deck. Deepwood Grizzly is solid, so is Wild Growth. Sagami Grovecaller wins games, simple as that.
Other than that, depends on what you want your deck to do. For example, stacking Spirits of Rebirth is brutal, but you sort of need to build a deck around their synergies. Then there's the cards that need a lot of Forests, and that will eventually win you the game just from sheer value.
Also, Dash, and especially Jump, are really strong keywords.