To achieve perfect waves or curls in your hair, follow these steps: 

1. Start with clean, dry hair: Make sure to wash and blow-dry your hair before styling it. This helps prevent frizz and ensures that the style holds well. 

2. Apply a heat protectant: Use a heat protectant spray on your hair to shield it from damage caused by hot tools. 

3. Section off your hair: Divide your hair into sections using clips or ties. This makes it easier to curl each section evenly. 

4. Choose the right size barrel: Select a curling iron with the appropriate barrel size for the type of wave or curl you want. For tighter curls, use a smaller barrel; for looser waves, use a larger one. 

5. Curl small sections at a time: Take small pieces of hair (no wider than the width of the barrel) and wrap them around the iron in one direction until all strands are curled up towards your scalp. 

6. Hold for 10-15 seconds: Hold each curl on its own wrapped around iron section for 10-15 seconds before releasing so that they have enough time to set properly. 

7. Release carefully: When you release each curl from around its corresponding iron section don’t pull too hard – gently let loose instead!  8. Finish with hairspray : Once done setting all curls wait few minutes then apply some hairspray over them which will help maintain their shape throughout day.