Download Picmix for your mobile phone HERE.

Open the application, you'll see a small white centered picture with cursor blinking on it. Press Menu » Tools » Resize picture, unmark the "Keep Aspect" option and resize to "320" or less on both height and width. Now Press Menu » Add » Add Picture, move to the location of the first picture [Note:: the picture must not exceed 180kb], press on it to add and press Menu » Tools » Resize picture to resize the picture to a smaller resolution like "100" on both width and height. Now move the picture to your desired position and press "Done" to embedd. Now use the above step to locate the 2nd, 3rd and 4th pictures if any, resize and move to desired position and embedd. After adding pictures, press Menu » Save picture » Save to JPEG and your mixed pictures will save in the "Graphics" folder of your phone memory.

To use a desired picture as watermark or background, press Menu » Open new, select the picture and resize to about "320" or less on both the height and width.