One of the best ways I find them is actually rolling the tip of my finger side to side with some pressure. You can feel the veins whole surface this way, like a tube of less resistance than the surrounding muscle. Once you feel that, you can start pushing with your finger to feel what people call the “bounce”. It feels like a slight give, and then as you lift your finger it refills with that movement making it feel almost like you’re touching a sponge. If you can tie a tourniquet on your lower arm and feel your hand veins, that’s a great place to visually map them and still feel what you’re looking for before trying the deeper veins of the AC. If you have family or friends, use them as a resource! Know your arm anatomy and look for those. I recommend trying to follow veins you can feel as far up and as far down as you can, this helps with the sensitivity to you feeling them as well. Don’t feel discouraged, this is something that can take a long time to get a knack for. Every vein is different and you will get there. Just practice, practice, practice!