Use the Wider Starter Strip
The bottom of the starter strip (the part the bottom panel hooks on to) should be at least 1 in. below the top of the foundation, but the lower the siding is installed, the better. It protects the sheathing from rain, snow and pests. Most suppliers sell two sizes of starter, 2-1/2 in. and 3-1/2 in. Spend the extra few bucks on the wider stuff and start your siding a bit lower.
Cap the Corner Posts
Mice, bees and all sorts of other critters love making their home inside vinyl corner posts. Keep these pests out by capping each post before you install it. Start by cutting off a few inches of the J-channel portion on the post. Fold back the remaining flaps and gently tap a crease into them with your hammer. Notch the flaps so the post will fit snug up against the wall. The posts will crack if they're not warm, so if it's cold outside, lay them in the sun or bring them into the house before you do this.