Here's an example of what I have sent to triangulated groups:
All of your are matching my dad (George Athey) and one another on a segment of chromosome 9. Since everyone is sharing a segment, it means we all share a common ancestor. I would like to work with you to try and determine that ancestor.
The following kit names on FTDNA match my dad and each other: Robert William Hartman, Marilyn Worsham, Dennis P. Mathews, Patricia Ann Webb, Brigitt Deanne Kergan, Allison Marie Key.
These are all sizable segments that are being shared with my dad: Hartman 39cM, Worsham 31.3cM, Mathews 21.7cM, Webb 44.6cM, Kergan 27.7cM, Key 28.5cM (who's also sharing a segment on chr. 4 with my dad).
Do you have a family tree I can look at? You can view my dad's here: http://www.wikitree.com/treewidget/Athey-68/5
Surnames include: Abbott, Athey, Bapst, Barnard, Barnes, Berry, Biggs, Bradford, Bunker, Burns, Casto, Coleman, Daminig, Dominick, Dominy, Dorminy, Estes, Estridge, Fallis, Fry/Frey/Frye, Fussell, Gorham, Hatcher, Jones, Kelly, Kirkland, Lamb, Leedom, Macy, Maurer, Miller/Mueller, Mowder, Odom, Pabst, Reulen, Rose, Rouse, Russell, Schuler, Simms, Snell, Stroud/Strowde/Strode, Thrift, Williams, Worth.
Hope that you're interested and that we can figure out our common ancestor. Thanks!
I usually hear from at least 75% of the people. Sometimes they tell me they don't understand, in which case I will go into more detail. In the case of matches that are from Gedmatch, I list the Gedmatch ID # of the person that matches (since some people manage multiple kits). If I have located a common ancestor with one of the people, I mention that person but point out that it could very well be a different ancestor. If I have seen that numerous of the matches have ancestors in a specific state or states, I mention that also.
I've learned that keeping it pretty simple in the first email is the best way to go. When I provide too much information, it seems to confuse a lot of people. While I'm very 'into' DNA, my experience is that the bulk of the people have very little or no information about DNA, triangulated groups, or mapping chromosomes. K.I.S.S. is very applicable in this situation!