Fred, KT5X – AKA WS0TA, recently put together this document with a lot of antenna ideas (and what led him there). I’ve used information Fred shared with me to make the antenna traps for my tri-band EFHW antenna (I really gotta write about that sometime!). Fred asked me to post this PDF so he can share this info for anyone that might need it.
One of the particularly intriguing (to me) ideas in this PDF is the “beam” antenna on page 4. Enjoy!