With the man seated, the best position for a blowjob is kneeling directly between his legs. If he must keep
his pants on, around his knees or around his ankles, kneel or sit next to him with your head at penis level.
Try to get yourself into a position where both hands are free to roam around his body. Also, try to give yourself
several degrees of movement up and down so you can change angles or work his penis in circles with your head.