Nice
Vigilance
SEALs
1) You could rush the main roof, and take out some guys from there.
2) Make the window hop on the right side, go into the church window and snipe from there (or on the balcony or building right beside the church)
3) Rush the alley near the left side and snipe down it.
4) Lay in either shadow of the trees (black suit helps) with an SR-25SD

If you get it right, you can snipe the normal stuff from the tree, but also the right side of the tunnel, IF you get in position right.
5) SEAL spawn roofs (not advised to stay for too long) But a little trick to see the Terrorists 3 window roof where people snipe from a lot is:
Hop onto the main SEAL roof beside the building, go to the very right edge or tip of it, stand up and zoom in, you can see their spawn perfectly and no sniper from terr EVER looks there...
Terrorists
1) Rush bikehouse (house beside the lieing down bike...) and snipe from either window, or go outside and snipe laying on the bike.
2) Go on either roof at Terr spawn, blowing out the gate on the one with C4 and planting some crafty mines helps too IMO.
3) Go to your bridge, the right corner of it, from there you can snipe the tunnel (both sides) and the alley to the right.
4) Rush the church windows and snipe SEALs still near their base, or hop down and go rushing onto the SEAL roof and snipe from there.
Bah...
The Mixer
SEALs
1) if you start close enough, go to the corner of your spawn and snipe the bridge and anyone going across it.
2) Go left and up the stairs, snipe from that little platform up there; or keep going and snipe from the building right near the small bridge at the Terr spawn.
3) Go into "The Mixer" and snipe from top window.
4) Go to the top and snipe anyone trying to get into top extraction, then move into the extraction and snipe the bottom.
5) Go left but instead of going up the stairs, go beneath them and hide in some bushes and snipe the Terr roof or any Terr rushing the trains.
Terrorists
Ha, here we go
1) If you start near the bridge, don't go out, but snipe from either of the 2 windows there and get any SEAL trying to snipe the bridge or any SEAL trying to go lower extraction not via tunnels.
2) Snipe from main roof (not recommended IMO, too open...)
3) Go to the bottom extraction and plant some mines whereever you like, now go to the far right corner of that extraction, and prone snipe in the bushes.
4) If you start at bottom, go to those broken cars outside, go RIGHT where they join, and snipe from there; OR lay on top of one.
5) If you start near bottom, rush the stairs on other side of trains and snipe from them; OR go up the stairs and go really anywhere you want (right, left, to top extraction) and snipe.
4) If you start near bridge, go outside but dont go across, go to the edge of the platform beside the bridge and drop down
CAREFULLY to the ledge beneath it, takes some practice.
5) Rush right side and snipe from either the little building near the bridge, or keep going and snipe at the tankers, or keep going and take anyone out at spawn or mixer and snipe from "The Mixer"
Thats all for now....sorry I didn't really do a lengthy description, but the room is up soon today so....had to hasten on my post.