I use either Vaseline to base my scalp or this product I found at the Asian BSS, its by Isoplus and its a small bottle that says Pre-Relaxer Base. Both work wonders though. My scalp is very sensitve.
I relaxed my own hair on the 16th and before I did it of course I didn't manipulate my hair and scalp too much. I gently parted my hair into the 4 sections, I based the parts with some Blue Magic and based around my edges and ears. I also put some Protectiv Break Free on the already realxed ends of my hair. This worked out really well for me. I was able to put the relaxer on and go back and smooth it without even the slightest tingle.
i don't base. for me, what makes the difference is where I start on my head. if i start where the new growth is thickest and work my way towards the more sensitive parts (in a timely manner), I'm good..
I use Affirm Gentle Assurance or Sensitive Scalp Base (at my local BSS). I try not to manipulate, scratch or comb my hair the day before. Also, I usually try to wait 3 to 5 days after I wash to relax. If not I can burn, burn, burn