Valry - While you're creating your montage, you will need to preserve the layers so save in psd or tif. Once you are sure you have the final composition, you could save in jpg but this will reduce the image to a one layer one - with or without compression.
Joy - there are lots of photomontage/collage images around to give you some ideas of what you might do - in fact most newspapers and magazines use these techniques. The most important thing is to think about what
you want to say visually -
do you want a simple statement or something more complex?
how do you want to use colour ?
are you going to use different sized images?
do you want to include text?
are you going to use parts of image?
do you want hard edge or rough or mixture?
with layering - are you going to use different levels of opacity so that different images show through?
what background effect do you want ? - in aesthetics/art, the space between the images is as important as the images/objects themselves
Once you have some idea of these issues, you will also probably have some ideas in your minds eye. It's then really a matter of what I like to think of as 'playing' with the images - grouping them, moving them apart, taking them back, bringing them forward, making some brighter, subduing others,making some smaller/bigger, etc, until you get to a total effect that is near to what you want - your message.
Den will take you through these stages technically but it is vey difficult for us to show you how to achieve your own personal aesthetic.
Think that's my input for the time being.
Feel free to ask anything about what I've said.
Gadget
