Darwoth's advice is the best in this thread (including his assessment of those who feel otherwise).
Maximizing your production/industry is the best thing you can do. There is no cheat guide, no easy way of doing it. Not since purity was adjusted. I've seen people use a single element of all types of produce to level and others who use a variety and the best foods of each. Some people swear by pumpkin pies, others have begun to experiment with corn as a result of this new update.
The sheer amount of recipes existing should tell you that the devs don't want a single right answer to lead your character from 5/5/5/5 to grand numbers. That would be a grind and not an experience.
My suggestion would be to maximize your industry in a way that meets your play style, which may be less that Darwoth's own allows for. The upkeep isn't that expensive for claims. If you are finding it too expensive, you may want to evaluate the way you play. Are you in a comfortable position to make/sell items for silver, specifically iron bars? Either way, without increasing your output, your advancement will be like pulling teeth. More farms = more food. After you have your farms and your nicely sized claim, then you can figure out what to plant and what mixes work best for you. In the meantime, don't forget defenses (big bases = nicer targets) and that you're going to want to keep working on your humus purity to increase crop purity once you're rolling along with a nice production base.
*edit* - Yes. Go ape on your fields. Vegetables are and always will be a better option than meats until husbandry comes around. Fishing is a waste of time. Rake it harvest and munch down. For information on recipes and their base values, see the wiki. So far as recipes involving higher tier crops go, I don't think anyone has hard numbers yet, but we have seen they get much better . Also, try making a friend. Bases are easier to manage with a buddy.