The importance of a warm-up.
Have you ever noticed that after you’ve been practicing for an hour or so everything suddenly becomes easier to play? Then the next day when you go back to it your back at square one? Using a warm-up will help you get to this “easier” place much quicker. I recommend spending a lot of time doing a warm-up and getting prepared. You never want to play with cold hands, it can actually be very dangerous. A routine warm-up can increase your playing level and allow you to play for longer durations, lengthening your practice time. I highly recommend doing at lest 5-10 minutes of warm-up per practice session.