To start, I want to explain you some "language" that I use in this guide.
For sizes I use, as an example, 100 (width) * (by) 100 (length), which is an avatar size.
I'm Dutch and 13 years old, so my English isn't perfect. I hope you like this guide :].
(I will add pictures soon)

AVATAR SIZES

A normal size of an avatar would be between 100*100 and 150*150. 100*150 and 150*200 are also frequently used sizes. I prefer 100*150.


SIGNATURE/TAG SIZES

For a normal signature I use 415*115 or 433*133. A good size would be between 400*100 and 450*150. You also have signatures like this one, made by me a long time ago:

Spoiler:

I used 125*450. A good size would be between 100*400 and 150*450.

Navigation bars
As you (should) know. A navigation bar is made of different pieces. Like, the home, portal, etc. are all different "files". They'd look the best at 80*20 !!!
You should remember that well, because, especially, on the E.S.F. I see many bad sized "nav. bars".

Banners

Coming soon...

Other

Smiley

I never saw anyone here making a smiley (except me), but I'll still post it.
This forum has many smilies, like:
:lol!:

Aren't they great? Well, keep in mind, that these are made by PROFESSIONALS, so don't be disappointed if yours are not as good as these :]. For a good size of these I'd take the size of the ones on this forum, which is 21*22. 24*24 or 32*32 are also good sizes. For bigger smilies I'd suggest 48*48.

Icons
For icons you have a few sizes.

128*128, 48*48, 32*32 and 16*16.
16*16 may be too small. 32*32 too. 128*128 may be too big, which makes me suggest 48*48.
48*48 is the perfect size for icons.


Guide written by Chainyyy, A.K.A. SvanGraphics

Don't copy this guide without my permission.

Thank you.

If you have any problems, want to request something, feel free to PM me ;].

(It's not done yet, I will add more soon.)

nice guide, although sizes arnt the most important thing when it comes to GFX

Nice, sticky this

Locked

@Pikmin --- Yes they are. A wrong size and your project is failed.

include userbars too and good guide

Also what about desktop wallpapers or just wallpapers?