I pull and drink at least one straight shot every day. I use it for a quick burst of caffeine and to judge whether any adjustments are needed. Sometimes I'll pull and drink a second straight shot, especially if I make any changes. Then I'll pull a shot for a milk drink that I can linger over while I read the morning email. That's backwards from the Italian way (milk drink first), but in this case I'm my own barista

. If I consume any coffee after the milk drink, it's straight espresso or straight vac pot.
My routine is to pull into a hot-water warmed cup, stir with demitasse spoon, inhale the aroma and compare with the aroma of grounds, take two small sips to judge the shot, if OK continue with small-medium sips to the bottom, often looking out the window and contemplating the flavor (and if I'm dialing in, thinking about what I might do to change the shot profile.) It's usually gone in less than 30 seconds, one minute tops.
The first sip is often less balanced than subsequent sips, maybe due to more crema. The second, third, fourth sips tend to reveal the best the cup has to offer. I sometimes swirl the cup as I go along. Sometimes the last couple of sips are slightly sour or too cold, the former if I didn't stir enough and the latter if I took too long to drink. I'll sink the remainder when that happens.
That's my routine at home and at the best coffee bars. In lesser venues, if the first sip isn't drinkable I dump a ton of sugar or sweetener in the shot and stir. Sometimes that rescues the shot, sometimes it makes matters worse (typically, sweetener makes it vile.) I learned to do that in France and Spain, where sugar helped the shot almost every time.