yeah, start low. Also you may want to use something other than NYC for a pre-workout stimulant, since it makes you feel a little off. I remember when the yohimbe craze started about 4 years ago and I didn't know the correct dose and was feeling funny. I took my blood pressure after a dose of ECA and yohimbe, and it was through the roof.
Duchaine once wrote that the fatburning effect of yohimbe will last all day, and that you should take your dose at one time in the morning... this way you can use ephedrine before you lift without the high blood pressure issues. I got good results off this... can't remember what the dosage was though.