Tag basics tutorial/explanations
If you enjoy creating AWESOME WHITE LIGHTS everywhere on your tag just to have someone go up and say, "looks like crap dude", then you need to learn that lighting is not just a white brush dot on the canvas. Lighting is a bit more in depth than that, and there are various kinds of lighting that you could possibly apply to your tag. Of course, that COMPLETELY depends on the stock of the tag, and effects you are adding. For basic use, you want to analyze the stock prior to actually adding a ton of effects and random splotches of ugly white brush dots everywhere.
1) Say you're a Paramore fan and what to make a tag using this stock image (http://www.weeklyreader.com/readandwriting/content/binary/paramore2-1.jpg). How would you effectively manipulate the lighting to best suit your tag? First of all, look at the stock before you do anything. Where's the light originally coming from? You will basically have to work with the light coming from that direction since it looks a lot more natural. In this case, the light is coming from roughly a 45 degree angle in relation to the front of her body, and therefore, if you were going to put some white brush dots anywhere, put them in the bottom right corner of the tag (assuming you don't horizontally flip the stock) so that it doesn't look like crap! If you put the lighting from the top left or bottom left, you're basically ignoring the stock itself and just creating cruddy effects that no one except for noobies will enjoy.
2) Don't ever just use the color white. I've seen it so many times it makes me want to puke. Want to know why you should never use white? Because pure white light would blind the hell out of your retina AND it looks like crap on a tag. You're probably asking me, or yourself, what color of light to use. The color? Doesn't matter. You could use a green light and I wouldn't care too much other than the fact it'd probably look worse than the vomit you get from food poisoning. Whatever color you choose is fine, but it's how you apply the color to make it look like real light. If your lighting is really, really, really saturated, then the areas where the light hits the stock have to be the color of the lighting as well (let's use green since I already mentioned it). If the light is really intense, it's fine to use white (I use off-white which is close to white, but not exactly white), but it should radiate the colour as the light ventures off from the centre of the source. Here's an example using one of my old tags from 100 years ago.
Credit to my budden Ken
Yes, the light looks white, but you can tell that it would be light from the sun since it radiates a yellow colour as the light intensity weakens. By understanding how this works, you can make tags that have a lot of lighting to look a lot more natural than if you were to just put white. Also make sure that when you add lighting, don't just leave the stock as is. You will want to manipulate the stock a little so that it works with the lighting. Understanding colors is a great asset when working with lighting. If you take a look at the example, the light is yellow, so he darkened the shadows of the stock and given them a blue/green hue. If you had a red light, then you'd want to have shadows that were slightly more green.
3) Lighting from effects that you create are also important too. Say you had a stock of some guy looking down at his open hand, so you created some kind of awesome red energy ball or fire. What would you do? You'd add some lighting around that specific area so that the effect becomes integrated into the tag, and just isn't sitting there. Being able to effectively integrate such effects is what makes a tag that much better.
4) Lighting cannot only add a more natural feel, but add depth if used correctly. Say you had a tag that was all renders and was really busy, but despite all the 3D effects, it looked flat. Well, by adding lighting and shadows to certain areas, it creates a sense of how some things are closer and farther away from each other just by how you integrate the lighting. You can create a sort of "tunnel" effect with proper use. If you take the previous example with the monster and intense sunlight, you can observe how the intense light creates a sense of depth. Since the light is so bright and shines inwards towards the viewer, it gives them the sense that the light is far away, and everything else in the tag is much more closer, effectively creating depth.
5) Lighting is not without shadows. Light and shadows go hand in hand, but there will be times when the shadows just won't work.
All in all, everything I've said only works if you practice and are creating a tag where lighting is necessary. Some tags just look bad no matter what kind of lighting you put in, and the moment you remove it, it's amazing. Just because it looks nice doesn't mean you should put it in practice all the time. With my current sig, there is no light source whatsoever, yet it still looks good. And remember, lighting does not only effect the stock, but everything around it as well.
The stock you choose determines the flow of your art piece. For example, if you were to choose a stock such as this:
There is virtually no flow. But if you were to choose to use a stock like this:
You can easily see the flow in the stock because he's pointing. Flow's really easy to master because all you have to do is determine which way your stock is moving. PICK DYNAMIC STOCKS! Crappy stocks like that dog suck and make crappy tags. If you mess up on flow everybody gets laughing rights because it's really hard to screw up.
Also known as TEXT. Text is even harder than light to master. Even some of the long time veterans don't have it down. Text isn't always necessary, and should never be forced. This means that not every tag needs text. If it doesn't follow the flow, or even just doesn't feel right, then just take it out. More often that not, the tag will look a lot better. If you're a beginner, you'll be better off just leaving it out. You can gain insights about typography and how to improve it here. There's also a typography tutorial on AppendixSquared but I probably shouldn't post it here since the watermark has swears. (:
I guess that's really all the basics you need to know.