The first key to any reception is to get above obstructions that exist between you and your target, as radio frequency reception of any kind (satellite, microwave, Radio and TV) are for the most part "Line-of-Sight" dependant. The fact that some receptions occur without line of sight is due to phenomenon not applicable in this discussion. As you increase your target distance, you increase the territory you must account for in maintaining line-of-sight. What tall building and air traffic exist in this corridor, no one can account for. Aircraft are very good at messing up reception for a number of reasons, even when flying way above the path, again removed for clarity in this discussion. Height, is therefore key in optimizing your ability to capture the best line-of-sight possible to your target.
Small Directional Antennas are good for HD TV Reception in the 0 to 30 Mile Range...
For Short Range Direction TV reception, there are typically 3 major types used; Corner Reflector, Yagi and Bowtie, not in any particular order.
These Antennas are of Low Profile and Typically have a Asthetically Pleasing appearance which can a Plus when dealing with Home-Owner and Condo Associations. Their Small size lends them well to Attic installations to be completely hid from view. Some Considerations in Attic Installations would be; to keep wiring and other metal obstructions away from the Frontal view of the Antenna as not to impede reception in that Direction, and that any Amplifier that you might be using to enhance reception and/or distribution to other TV sets in the house be colocated with the Antenna as to reduce loss of signal unnecessarily due to distance between the Antenna and Amplifier, as well as to offset any loss in Antenna Gain from Roofing Materials used in Construction.
Indoors or Out, I always try to Mount the Antenna in a Position and Fashion that will lend itself to a maximum Angular view of the Horizon so a sweep with the antenna can be performed through and Past the intended reception Direction(s). This will insure that you are centered on Target (finding the "Sweet-Spot" for them all), and that if there are other Broadcasts available to you that were unknown previously, you can amend/supplement your current Antenna installation to add these New Channels to your Stockpile.