Start dreadlocks in straight hair is to divide the hair into sections using rubber bands, then backcomb the hair in each section to form a dread. Although it is more difficult to start dreads in straight hair than in curly or kinky hair, it is possible to achieve tight and even-sized dreads with straight hair using the backcombing method.
Before you begin backcombing your hair, you'll need to decide what size you want the dreadlocks to be. Thicker dreadlocks will tighten sooner but will be difficult to comb out if you change your mind.
Make sure to start with clean, dry hair. It's best not to use conditioner. To begin sectioning your hair, take a section of hair of the desired thickness and place a rubber band around it near the roots. Enlist the help of a friend if necessary. Once all your hair is sectioned, check to make sure each section is of roughly equally thickness, and fix any sections that are unequal.
When all of your hair is sectioned, it's time to begin the backcombing. Backcombing is similar to "teasing" your hair. Take a metal comb and begin combing a section of your hair toward the scalp. Start close to the scalp and move to the end of the section as the hair bunches together to form the dread. It helps to twist the section as you comb and smooth the backcombed section with your fingers every few strokes to prevent loops and frizz. Once you've finished backcombing each section, secure the dread by placing another rubber band at the tip.