Photoshop files tend to get very large, so it might get really inconvinient to transfer them over the web. Here are a few tips for making your PSD file sizes smaller.
You can always merge layers that you won't need to edit separately.
By hiding all the layers inside a Photoshop file, or overlaying the entire file with a single color layer, for example white, will drastically reduce the file size.
Crop the Canvas
Graphics that are off the canvas and not visible also affect the file size. Crop your entire document to delete the graphics that are out of the bounds and not visible in the file.
Choose a file compression tool like WinRAR to compress your psd into a .zip file.
Rasterize Smart Objects
Does your phohoshop file contain smart objects? If you don't need to scale them up anymore, or they are not used as placeholders, you can rasterize them.
NB: These are simple general tips for making your psd file sizes smaller. Many of the tips cannot be applied on PSD templates that are going to be uploaded to Mediamodifier