There are many ways of improving your sound. Not the least of which is buying all new gear. But before you rush out to "Gear R Us" and max out all you creditcards, including the gas card, I'd like to touch on some ways to do it for free or for pocket change.
Increase Your String Gauge
The next time you're going to music store to buy a set of strings, buy a heavier set. Heavier strings sound better. They provide more mass or more tone and they tend to ring longer. If you're playing your electric with 8's or 9's try bumping up to 9's or 10's.
Stevie Ray Vaughn sometimes used heavy-gauged strings as thick as .013-.060. You'd be hard pressed to argue than SRV wasn't a tone king. Now to be fare I have to tell you he did detune his guitar a half-step to Eb-Ab-Db-Gb-Bb-Eb, making minor 3rd bends almost doable.
Now if after years of playing with 9's that set of 10's just feels way too heavy, then try a set of 9.5's. You can find them if you look. You could use that as a transition set. Or you could use a "light top heavy bottom" set to transition. One trick I did recently was when I ordered my last guitar, I had it strung up with heavier strings then I normally would've used, but now I've only known that guitar to feel that way. In essence I fooled myself. I play that guitar all the time and it sounds great.
For some reason like Starbucks' "tall", "grande", "venti", nomenclature for string manufacturers is "extra light" means light, "light" means medium, and "medium" means heavy.
Acoustic players could switch from "extra lights" to "lights" or from "lights" to "mediums". There is an even more dramatic metamorphosis with acoustic guitars when you increase the string gauge. With both acoustic and electrics it's a workout at first but later pays in "tonal dividends".
Acoustic strings -
Elixir Strings Acoustic Guitar Strings, 6 String, Light POLYWEB Coating
Elixir Strings Acoustic Guitar Strings, 6-String, Medium NANOWEB Coating
Ernie Ball 2003 Earthwood 80/20 Bronze Acoustic String Set, Medium Light (12 - 54)
Ernie Ball 2004 Earthwood 80/20 Bronze Acoustic String Set, Light (11 - 52)
Electric strings -
Elixir Strings Electric Guitar Strings, 6-String, Light NANOWEB Coating
Elixir Strings Electric Guitar Strings, 6-String, Medium NANOWEB Coating
Ernie Ball Regular Slinky String Set (10 - 46)
Ernie Ball 2627 Ernie Ball, Beefy Slinky String Set (11 - 54)