I'm not sure if it's been mentioned, but an inflated blood pressure cuff is a fantastic tool in IV starts to replace tourniquets. They provide more even pressure and are much more comfortable to the patient and I doubt you'd miss a big bp cuff while you may overlook a tourniquet.
The tightness of a tourniquet or cuff should depend on your veins. If they are already sticking up then you don't need to apply it tightly. I find veins blow more easily in those situations.
Don't spend 10 minutes searching. Usually I look for 20 seconds and give it a shot. The procedure isn't pleasant for the patient.
Make sure all of your supplies are ready. Tape pretorn (although our start kits have the little white cushioned adhesive holders). I also prefer to leave the loop tubing off and just use the lock cap. Have your saline lock primed and ready.
Clean per policy and do not touch that site again. Anchor the skin: hold firmly a few inches down and be sure to go in bevel up. I go as parallel as possible and once I feel the pop into the vein and see flashback, advance slightly more and push the cathelon in. Release the anchoring. Pop the tourniquet. Apply pressure above the site with my pinky to prevent a crime scene. Hold the cathelon with the same hand you're applying pressure with. Remove the needle and screw on your lock. I pull back gently to see if I get some blood. Either way after that I'll flush gently. If it's resistant I pull the cathelon back slightly while pulling back to get blood return. Once I do I flush gently while advancing the cathelon further. Securely dress your site and clean up.
It's okay if you don't get it. Be confident. Accept that you can't hit them all. Keep practicing.
~ No One Can Make You Feel Inferior Without Your Consent -Eleanor Roosevelt ~