Design your logos in black and white
Seriously. If you design your logo to one colour scheme, you may find it doesn't work in other colour schemes… what if your original colours clash horribly with some future piece of artwork onto which it has to be overlaid? You're restricting the flexibility of the logo enormously by designing it with a colour scheme in mind. Use black and white for all your strokes and fills plus one solid grey tint if absolutely necessary. If your logo doesn't work within those limitations, your logo doesn't work, period.
No effects. No bevels, no embosses, no gradient fills. If your logo needs these things to make it look interesting, then it's a boring logo. No amount of icing and sprinkles will disguise the fact that your cake isn't properly cooked; pretty much the same principle with logos.
Make a nice, strong logo that works in solid black and white. If your logo doesn't do the job in monochrome, scrap it and do a new one. Once you have a logo strong enough to catch the eye in black and white, you can spiff it up to your heart's content. But here's the thing: you won't need to.