What is the best way to create a photobook or poster?
Create a new set/album/gallery with high resolution images (300 dpi is optimal). If your current images are low resolution (72dpi web-optimized images), you can improve the quality of the output by re-uploading the images with the higher resolution originals. Note that if you want titles or descriptions for your images, you will need to add those on the photo service website before you build your book or poster.