It depends on the project. If you're following a design that specifies multi-turn pots but you don't personally need the accuracy, use a single-turn pot. Alternatively, you can combine two single-turn pots for fine and coarse adjustment. If you only need the accuracy in part of the range - for example a higher precision current limit for lower values and coarser limiting of higher values - use a log pot. Otherwise, you're likely to use a rotary encoder. These are digital devices that require simple programming. To replace pots with them, you'll need an analog output. This can be achieved with a DAC, with filtered PWM, or with a digital potentiometer. For a more specific answer you'll need to ask a more specific question.