Is the place beneath Sukkah decorations still consider in a Sukkah? Can you make a bereacha leisheiv basukkah there? how large can they be before being a problem? what about long but thin streamers?
The Sukkah decorations should be within four tefachim of the sechach, and in this case there are no problems in sitting under them, irrespective of their size. If the decorations hang down beneath four tefachim this can be a problem (especially if the decorations themselves are four tefachim wide), and this should be avoided.