In general:
1. Something sexy right from the beginning.
2. Only break grammar rules for a purpose.
3. Describe the ticklish distress of the subject without using "HAHAHA." We know what laughter and giggling sounds like. Describe its qualities.
1. Well, I do have a tendency to put in a good bit of explaination before getting down to the tickling. Partly that's me, and partly that's because I write science fiction and fantasy. OTOH I do try to put in a 'hook' early on - even a sexy hook, depending on what one considers 'sexy.'
2. I would add: When you do use broken grammar - or deliberate misspellings - use a light touch.
3. I rarely use "HAHAHA!" When I do, it's because the 'lee is trying to speak arough her giggles, and even then I avoid going ALL CAPS.
The worst thing I've seen along those lines is going all-caps with an increased font size.
Specific to my own tastes:
1. An element of trickery, craft, deceit, and villainy in the way the tickler lures/stalks/ensnares his ticklish damsel.
2. Damsels who misplace trust in their soon-to-be tickle tormentor, not knowing what lies in store.
3. Sadism, without physical harm.
4. Sexual teasing of the damsel, whether implied or explicit.
It sounds like our tastes diverge, unfortunately.
1. I try to avoid "Ler vs lee" as the source of conflict or tension in the story. When it is the story-conflict, I try to make it a lighthearted and friendly one.
2. I particularly go for damsels who
enjoy being tickled. Along with trying to avoid ler vs lee, I also try to avoid "damsel hates to be tickled, but..." I have used that last, a number of times, because it's too obvious a conflict to ignore. But what I really prefer are stories with lines like, "I beg the tickle, master!"
3. I'm really down on sadism. In fact, a major motivator for my own writing is to have bondage without sadism, and tickling that's something other than the WORST TORTURE EVAR!!! Instead I'll try to subvert the idea of tickling-as-torture, or I'll avoid it altogether.
4. This I can go along with. Maybe not all the time, but much of the time.