My go to staple for Sisterlocks curls are Soft Spikes. I have used them since around the first year and they always produce nice curls. Plus they are soft. I go to sleep on them with no problems.
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Here's a brief description of how I used them.
1. Start with damp clean hair. I added Jane Carter's Wrap & Roll.
2.Take the ends of a small section of locks. Place the ends of your hair in the end papers. Make a rectangle (ish) shape with the papers.
3. Roll your hair starting at the straight end of the roller like a spiral or candy cane around the spike.
5. Repeat. I repeated this about 45 times. You may need fewer or more depending on the size of the curl you want.
6. When fully dry, remove the roller by sliding it out of the curl.
Now, these usually last me about a week. I do not cover my hair at night nor do I curl it again with anything in the morning nor sleep with the rollers in until the next time.