sometimes less effort is more, the main thing which i think is impotant is getting them level, look at the pic what you've takin on long ex of the motor way, see how you to the left and its un-level? if you had been in the middle it would of looked a hole load better.
dont be scared to take time in a photo, and if you use PS to edit take some in different modes exposure etc and then you can edit them to what you think looks cool!
try different angles, black and white, flash...
other then all that tho your pics aint that bad, do what i do and take your cam everywhere with you and just keep snapping away, you'll get better the more you snap.
if you need photoshop go on pirate bay or youtube to get a free D/L
