Makashi opening stance.
The opening stance for Makashi was a single-handed low guard, with the blade angled downward at the practitioner's side
Opening stance for ataru
The opening stance for Ataru was a balanced two-handed guard: holding the lightsaber vertically with both palms, either on the right or left side of the body.
opening stance for Niman
opening stance for Juyo (revan)
shii-Cho opening stance.
The hilt would be held at hip height, the dominant foot was back with the tip of the blade pointing over the opponents head
Shien opening stance
Shien was a high guard position, with the hilt held in a two-handed grip above the user's head, and the blade angled upwards and behind the user. The dominant leg would be back, enabling powerful step-through strikes to be utilized. Shien does not use the backwards grip, there is another unorthodox style that does so, though its users are often Shien stylists as well.
Soresu opening stance
Back hunched, a good defensive posture, is ready for any occurrence but is also non-threatening. light saber at a position that easily can parry most attacks, Obi-wan uses it for most blocks.
if you want to know more then read here ... it tells us all the different stances, neutral, aggressive and defensive.