I am Amaranthim Talon, owner of Talon Faire and The Eyelash! Bar.
I have been in SecondLife since 2006. My experience in SL began like most others - a sense of wonder and a desire to explore. Nearly four years later that amazement at all that surrounds me still remains. I have also been very fortunate in the people that have allowed me to share in their lives. And now I contribute a little to the community of SL as well.
With my store, Talon Faire, I have been able to experience new levels of creativity untapped in me before- and it has been great fun! Recently with the opening of The Eyelash! Bar, I am beginning to see some success as an entrepreneur as well. You can follow my latest additions to the store on my store blog Talon Faire On-Line, 
I have few customers that have contacted me regarding the fitting of prim eyelashes, and I always include a note on the how to. However if you purchased lashes, from me or another store, the fitting is not difficult. Here are the instructions I pack in each box:
Turn on Highlight Transparent (Ctrl-Alt-T) to make this easier. Use a Posing Stand.
First make a copy of your lashes by right clicking on them in inventory, selecting copy, then click again in the same folder and select paste. You can also drag them on to a surface (BE CAREFUL! THEY ARE VERY SMALL!) and then picking up the rezzed copy.
Next - Stand on a pose stand. This will keep you still so you are able to edit away without moving. If you don't have one, there are many shops that give them away for free. Or drop me notecard, I have no problem sending you one.'' Right click on the eyelashes and select "Edit" from the radial menu. In the Build/Edit box that appears, check the box next to "Edit Linked Parts" - this will allow you to select only one part of the lash. Some lashes have three prims each, be careful of the parts that need to be edited so you keep the relative positions.
Sometimes, its only necessary to rotate them. You can do this by selecting "Rotate" in the build box, and using the red, green and blue circles to get your shape.'