Embarking on a winery tour comes with certain expectations. If you are on it for the first time; you need to be especially concerned about the preparations.
You need to understand the area you shall be visiting. If you are on a guided tour, then you shall have it planned out, with a tour operator who understands the area. But in case you are part of a group that is there by themselves, you need to have maps, whether paper or electronic, to help you get around. Vineyards are far from urban centers. You do not want to get lost out there.
You also need to make sure you have had a proper meal before starting the tour. This shall help you not get intoxicated too fast. If you are a regular drinker, you may withstand more quantities of alcohol before getting drunk. You need to find out more about your body. You can improve your tolerance by taking a glass with each meal some days before the tour starts.
There shall also be sops at the winery you need to visit. You should find certain types of wine not common back home. Their prices shall also be friendlier than what you get elsewhere.
See if they can squeeze in a private tour. In case they do not, there are still the group guided tours. You will most likely get private tours if you are there when they are not busy.
Before paying for wine tasting, find out if they have complementary featured wines. Those, in turn, help them advertise their products.
In case you are not well versed with wines, ask them to give you a short course. They shall gladly tell you how to explain what you are tasting, and how to select the best wines for each occasion. You could also get some education through online wine courses before planning such a tour.
You can ask to take some of the wines you are interested in buying before you do. You will hear of cases where the wine one thought was the best ended up not being so. This is how you end up with something you will like, or something better.
Do not end the winery tour before you have taken lots of pictures. This is how you preserve those wonderful memories, apart from the wine you shall take home.
You should have planned for the right person to drive you away after the tour. Since there shall be quite a few glasses of wine consumed all around, none of you should be in the driver's seat when you leave a winery. There is a high likelihood the wine will impair tour driving and lead to an accident. You also do not want to get on the wrong side of the law. You need to conduct yourselves with caution while on tour abroad, and not infringe on the local laws. Learn more about wines at https://www.encyclopedia.com/sports-and-everyday-life/food-and-drink/alcoholic-beverages/wine.