Prepare the cut end
Cut with sharp snips or scissors and keep the strand aligned. If the end has spread, smooth it between your fingers or trim it again rather than twisting it into a hard point.
Choose a working length before threading. A shorter length is easier to control and less likely to develop a knot while you are trying to focus on the eye.
Bring the eye to the thread
Hold the needle still against a light background, then guide the thread through with a relaxed hand. Squashing the strand flat can make it wider and harder to pass.
If the eye is consistently difficult, check the compatibility of the needle and thread. A needle with a cleaner or larger eye may solve the problem more safely than repeated attempts.
Secure the working strand
Once threaded, let the two ends hang evenly or use the method suited to your stitching style. Avoid a bulky knot that catches on the cloth unless the project specifically requires one.
Keep the needle on a pincushion or magnetic holder when not in use. A secure resting place prevents the fresh thread from being dragged across other tools.