Most Kohanim are unaware that there are specific kavanos (concentrations) one should have while duchaning (blessing). I personally follow the kavanos of the Amudei Shamayim which is as follows:
Yivarechicha Hashem - May Hashem increase your children and your posessions
V'Yishmarecha - and protect them from harm
Ya'er Hashem Panav Eilecha - May Hashem brighten his angry countenance thereby changing his attribute of Judgement to Mercy
V'chuneka - And favor you, even if you are unworthy
Yisa Hashem Panav Eilecha - May Hashem act favorably toward you
V'yasem Licha Shalom - And grant you Peace (the only vessel capable of containing unlimited Blessing).
Credit: ArtScroll's "Bircas Kohanim"
There are many Kohanim and Jews who also don't know that the congregants MUST be in front of the Kohanim to recieve the blessing. I make sure that I am standing closest to the Woman's section so that when I wave my hands I am including them as well.
When I duchan I really try an feel an intense love for all the congregation as well as the entire house of Israel. I try and really open up my heart and forgive all those who may have wronged me.