There's one last thing to do though; rotate your arms into
angles and smooth off the shoulders. Also make sure your limbs are
slightly bent at the elbows and knees.
Keeping the legs apart may help when weighing the verts to bones but
may also make rigging more complicated so use your own judgement
here.
The rotation of the arms is to get them into a more relaxed
state. Arms kept in a straight T-pose would cause faulty shoulders
when animated because most of the time the arms will be close to the
body.
The bent limbs are needed because an IK solution needs an angle
to work from. Make sure the bend is in one axis only though (for
example the arm is straight seen from front but slightly bent when
seen from top. Likewise the leg is straight from front but bent from
side)
Basically try to model your character into as much of a relaxed
pose as possible. This will reduce unnecessary stretching of
polygons.
That's it! Hope you found it helpful.