After completing the layout in Photoshop Elements,
1. Save the layered PSD file
2. Select Layer > Merge visible.
3. Image > Resize > Image size. Plug in 700x700 pixels in the top box. Click OK. (Check all three boxes at the bottom: Scale, Contrain, Resample)
4. Enhance > Unsharp Mask.
Play with the settings until it looks right but doesn't have halos.
5. Save the file as a jpg. File > Save as > change the format to jpg and save.
6. Now close the image. When it asks if you want to save changes click NO since you've already saved both the layered file and the jpg.