Since it's something many people struggle with while working digitally, today I will be discussing how you can achieve smooth and clean lines using digital mediums.
SAI Stabilizer Tool
Paint Tool SAI offers my favorite method of creating smooth lines with its easy to use Stabilizer tool that works with absolute ease and no need for complicated setting adjustments. It doesn't matter how shaky your hands might be, the stabilizer tool will still be capable of creating beautifully smooth lines for you.
As you can see, the stabilizer tool is easily accessed, and you can quickly and easily adjust the level of stabilization you desire. The lower the number selected, the least amount of stabilization is utilized, the higher the more. I generally leave the stabilizer tool set to the highest setting (as seen above), though I've found that sometimes if you're working with smaller brush sizes reducing the stabilizer