If you manage, run, or work at a store, you can say you tend it. If you tend the bar in a restaurant, for example, you serve drinks, dry glasses, and fill dishes with pretzels.
You can also say you tend something if you care for it. You have to tend a vegetable garden, for example, if you expect to harvest more vegetables than weeds. If you are inclined to do something, then you tend to do that thing. You might tend to let your homework go until the last minute and then stay up all night to get it done — probably not the most efficient way to go about it.