Hi there! As starting point, I’d say fresh, cold water, bread and incense, since are offerings that were commonly offered in the past and safe for all the Netjeru without distinction.
Anyways, here you have a little list of historically accurate offerings that are safe for all Deities. I’d personally suggest offering higher-quality goods for especial circumstances. Those are:
Bread, dates, honey, grains, beans, vegetables, fruits, beef.
Water, beer, milk, wine.
Cosmetic goods and incenses
Incense, linen, frankincense, myrrh, perfumed oils, natron, flowers.
Votive items, jewelry and figurines
Was scepter, Ankh, faience amulets, papyri scepters, jewelry, Wadjet Eye, Djed pillar, Ib heart amulet, ostrich feathers, Ma’at statuettes or amulets.
Goods should be safe, so please, don’t offer the Gods anything you wouldn’t use, eat or drink.
Thank you for asking me. May you be in favor with the Netjeru!