I'll third the "Hoochie Mama" call by primos, it is one of the easiest cow calls you can get and it works!

I like primos elk calls in general I use the Terminator & Hyper Lip Bugle, Hoochie Mama, Lead Cow reed call and several of the primos diaphrams as well. In combo the Hoochie Mama and lead cow call have worked excellent for me. I prefer the Terminator Bugle for tone and sound but is a bit bulkier than the Hyper lip, just depends on your situation (if you want a bugle that is small and compact try the Hyper lip, if you want tone and loads of sound the Terminator is among the best I have used.....both are pretty easy to use with some practice.)

Good Luck.