If you can tell the plugins you used, toss the texture out. I can spot eyecandy shiny bevels from a mile away.

Go by 16's (32x32, 128x128, etc) when doing textures and try to keep them square, it depends on the engine though.

Play with filters alot until you get techniques down for textures!

Play alot of 1st person shooters and stare at the walls for inspiration, don't do this in deathmatch :-)

Work from photos! Use the rubber stamp tool in photoshop to mix and combine photos to get nice realistic textures..

Recycle textures, it'll save you alot of time and keep a consistancy among your work. You can overlay textures and all sorts of things; very little work andit can give you a whole new texture in a very short amount of time.

Make custom brushes with very irregular patterns, they come in handy when you MUST make textures from scratch.

If your really serious about making textures or game art in general, buy a wacom drawing tablet. Even the smallest model works great, you can get one for about $200, maybe less. So save up that money you were going to use on your crack addiction.

DO NOT use alienskin eyecandy for bevels, you will look unprofessional, and if I ever see you on the streets I will cut your throat with the little metal thingy of an AOL floppy disk.. thats a really sad way to die. So please, take my advice, don't use plugin bevels, develop your own technique!