Any tips for getting blood taken?

Yesterday I had to get 3 viles of blood taken for a full MOT, it was my first time ever getting blood samples taken and it wasnt a good experience. Im not afraid of needles or injections but my veins were extremely hard to find and the nurse could only get a vile and a half from me, to top it off the sensation of the nurse searching for a vein with the needle made me feel nauseous and i ended up vomiting after my appointment 🫩.Any tips to not freak out /not vomit? (asking since I have to get 2 viles next week 😭🙏)