Choosing which cards to keep and which to discard requires you to be deliberate in your decision-making, & as the game goes on, you must continually weigh your options. If you can't use high-value cards to forr pattim sets and runs, they can quickly become dead weight, so it's important to avoid hoarding too many of them. Rather, concentrate on maintaining a well-balanced hand that includes both high-value and low-value cards. This will increase your options & flexibility for creating combinations. The cards in the discard pile can also be very helpful in finishing your sets and runs, so it's important to keep an eye on them.