The current theme is MACRO letters. A rule of thumb for macro photography is that the image (e.g. the regular size flickr photo) is larger than the object in real life. (For more about macro definitions see discussions here and here.) The closer the better. Ideally, the letter in your photograph should be no more than a couple of centimetres in height/width in real life. We want to see letters in gory close-up, with all their fibres, dust, pores, tiny imperfections and so on.