If you wish to use custom textures for Tick bar you can use the following tutorial of how to add them:

1. Place your texture in the \Tick\Textures\ folder.
2. Open up the main "config.lua" file and find the array called: Tick_TextureArr
3. You need to add your texture to this array, do the following:

Use the following line to add a new texture to the array:

[X] = "Interface\\AddOns\\Tick\\Textures\\MyTexture",

Replace X with the next free number available in the array, by default Tick uses 6 custom textures so the next free number by default would be 7. Replace "MyTexture" with the name of your texture in the \Tick\Textures\ folder. Reload the game completely if you are already in the game as the game won't recognise the texture without a full reload (not just a ui reload or log out). Also make sure you include the comma at the end of the line, and the file path is surrounded by double quotes ( " symbols) and make sure that the folder seperators are \\ rather than \ because a single \ is the escape symbol in lua and it won't recognise your texture, and will probably give errors in game.

Some notes to remember:

1. Textures I'm pretty sure have to be .blp or .tga files
2. You can't just use any old .tga or .blp file, it has to follow specifications.
3. http://www.wowguru.com/guides/custom-textures.php <--- this website has an excellent tutorial of making your own textures.
4. You don't need to add the type of extension to the end of your filename, WoW knows.