XRAY said:
oright so im really decent at photoshop not very expert as i am in css but i would like to know is there like a secret to making your designs in a high quality?note* im not referring to an image taken by a camera or w/e im talking about designs that are made with the ps software.here are a few samples i really liked and as you can see there the clarity of the image is amazing.
You need to use pictures of really high quality, like major said. Huge pics of 2500+ by 2200+ pixels in size. Having pics like this will ensure great quality at any size.
You also need to ask yourself what you are using the design for. When starting a new page, you’ll notice it asks for the size(either inches, cm, or pixels) and resolution. I usually measure in inches, as it’s easy and quick. But if you are trying to make like a website, then you would want to measure in pixels for a more accurate fitting.
The resolution is by far the most important component of the layout. Resolution is usually pixels/inch, or how many pixels per a given inch. The higher the resolution, the better the quality. It not only allows you to stretch your picture to larger sizes without sacrificing quality, but it also prints much more cleanly. The only problem is higher resolution takes up more memory. So as long as you have enough space your fine.
Good Resolutions (minimums):
For Printing: 150 to 200+ ppi
For jpeg: 100 ppi
For jpegs(high quality): 200+ ppi
For Posters, shirts, cd covers: 250+ ppi
For websites: 150+ ppi
Now, you can put whatever you want as the resolution. My standard resolution is 200ppi, but i’ll go higher if I really want to impress 
Usually though you probably won’t need to go past 300ppi.