Oh, and remember to keep descriptions brief. They're best off woven into the scene rather than dumped in a mega paragraph at the front and some scenes are best off with only one or two pieces of description in total. Don't feed bad if you generally let description fall by the wayside - just endeavor to include it a few more times or just try to be unique and original when you're doing it.
As some ideas for a tavern: "Boots drummed on the floor as the locals danced along to screeching and poorly tuned fiddles." "The soft thwack of fists on flesh could be heard coming from the corner." "A woman's high-pitched giggle is suddenly cut off by a man sweeping her up in an embrace." "A man groans by the fireplace, clutching his head, as a woman sweeps up the rushes." "Rain drums across the wooden planks with the odd drop landing in a few wellplaced mugs with a determined 'plink'." "The floorboards creak overhead with the sound of footsteps."
Humans don't tend to notice their noses very often but when they do it almost always matters. The sweet smell of spring flowers or the fresh smell of rain can perk folk up the first time they smell it. Generally though the main things folk smell are food smells (especially when hungry) and unpleasant ones. You don't need to overdo smell descriptions as they really should only be used at the first encounter. "The tavern alley reeks of piss and rotting cabbages." "The churned mud outside the tavern door smells like wet clay and horse dung - well, hopefully only horse dung." "The stale odor of unwashed men mingles with the stink of spilled ale and wet dog from the pooch that eyes you from the rug by the fire." "Mm. The yeasty smell of baking bread wafts out from the kitchens."
Let's face it. The ideal method of invoking taste is actually the taste test. Get everyone to pitch in some cash and effort to actually make some medieval fare. Provide a few fingers of ale or cider for people to drink though no more unless you want a tipsy game and all the silliness that often provides. True those drinks will be nothing like the medieval fare unless you know a reenacter or historical provider but they'll at least give people a starting point. Outside of a taste test you're left with a few simple descriptors (sweet, rich, sour, bitter, tangy, salty, acrid), descriptions of consistency (thick, chunky, slimy, sloppy, over ripe, soft, smooth) and comparisons to other flavors (i.e. "tastes like chicken"). Remember, though, that other things other than food and drink have a taste and oftentimes you can invoke it simply by mentioning what got in their mouth. Blood from a split lip (or the opponent), seawater, mud and weevils can all be deeply evocative simply by stating it got in their mouth.
The sense of touch is similarly ignored despite its importance. Temperature, such as the heat of the fire or the cold touch of snow, is important to remember. The dampness or sweat or wetness of rain. The weight of one's goods and equipment. How one's clothes chafe or how chainmail makes one's shoulder's sore. The sting of saddle sores. The roughness, splintery wood of a door. The unevenly stuffed straw mattress whose straw keeps poking the character while they try and sleep. The tacky ale left to dry on the bar (or worse, the seat). The muck tugging at the character's boots. The tickle of flies landing on skin or itch of mosquitoes drinking their feel. Touch can be incredibly evocative because the modern world is quite comfortable and we have methods of regulating temperature, keeping the weather out of our buildings, frightening away mosquitoes and making clothing and furniture that is quite comfortable.
Finally, and least importantly, there is the sensation of picking up objects. This is generally less important because when you describe a character cracking open a parchment book they will immediately have an idea of what it feels like. Similarly, there's no point describing a soft silk, as the players know that silk is soft, unless you're planning to contrast it with something else. The players don't want to hear your descriptions go on forever so pick the sorts of bodily sensations that they don't normally experience and would generally forget. Roleplaying games are deeply imaginative ones and the imagination tends to pull one out of the body. Try to do the opposite and push them into a new body, a body they are playing, by reminding them of bodily sensations.