During the game:

Get Aging: It's tricky to fulfill some contracts without high value wine and it doesn't matter how good your vineyard, that means you need to age the wine. If you can get a vine out and grapes harvested in the first two years at the latest then you can start aging. Turn one is great, but rarely will this wine be more than a 1.

Lots of Wine: This is a game about exporting wine and lots of it. You need lots of grapes to do that - especially if you are making blush or sparkling which will require combinations of grapes. I always prefer making lots of wine through the game, rather than relying on the big value sale to make the win.

Balance Visitors: I like to keep a balance between summer and winter workers, but if I know I am going to play winter workers (two of them with 3+ players) then I will probably have 3 in my hand that winter to pick the best two. This is a bit of luck mitigation / maximization but I find this helps.

Train Early & Often: I always focus on enough money and a worker to train. It's important to get the workers out and be able to take actions to build the engine. This also means that the free worker is important early game, but the more workers you have the less important that is.

Start Filling Contracts: It's tough to fulfill a contract but the earlier you can the better your chances. It's tough to get more than one worker on the "fill contract" slot in the late game, so an early contract is valuable. Don't miss out later though, once you start to fulfill you need to keep it at about one a turn. Best guess, 4-5 years in and you should be completing a contract a turn.

It's a Race: Don't lose sight of the race in all aspects. Players will be optimising and you can block their moves if you can predict them. Help build your way to victory and watch how the other players are going about it!

Early Vine or Worker: Early in the game, I find it helpful to take the player order spot which either gives you a worker (because of it's impact at the start) or the Vine. The Vine is earlier in the round (only no bonus can go earlier!) and the wine can help you get aging quicker or produce higher value wine.

Tour Money; If you are going to take money, you get more from doing the tour in the summer than the money action in the winter. Try to plan your winter workers and use spare to get more money through the tour.

Yoke when Busy; If this board gets busy and it gets hard to harvest in the winter, the yoke can allow you to harvest on your own board and then go straight for making wine. I find this a powerful way to get to score on a crowded board.

A More Aggressive Play Style:

Turn 1:

I view the strongest start to be to sell one plot of land, and aim to buy two workers on turn 1 (or turn 2 if blocked from buying them turn 1). This also means that the first two slots of the wake-up chart are critical. It is rarely worth having more than 2 plots as the extra effort to get them all harvested is not worth it.

Turn 2 - 5:

I find number of wine tokens is WAY more important than the level of the wine. The best contracts take blush or champagne, and since these take 2 or 3 grapes, it is trivial to get them to level 7-9. So with this in mind I always try to make sure each plot has a red and white grape in them, and the two plots I have, the white/red in one plot have a different strength than the other.

Turn 3-4:

You will need to have at least a medium cellar (I like having larger as well). The contracts that need just 1-3 wine strength are normally not worth doing.

In General:

I do not like to make wine without having contracts unless I need room to harvest more grapes. A wine made with no order is a waste of 2 to 3 actions.

The game will end fast. I have seen (and done) 15 points in one turn, so the moment people have a couple of grapes and are around 4 to 5 points, the game could end. There is normally a fight for fulfilling wine orders at the end of the game. This means that sometimes is it good to have a few good yellow/blue visitor cards that earn points (a bit of luck getting them).

Mama/Papa: The two best ones in my mind are the one that gives an extra worker, or the cottage. A jump on extra actions or visitor cards can be a major boost.