Don't really know if this is advanced but it's very effective and not widely done.

Any of you varmit hunters ever try calling with your MOUTH? No, I don't mean shouting "Here coyote!" I mean using the mouth to imitate a dying rabbit. In fact, if you listen to "mouth calling" followed by a commercial hand held call, there is no comparison. It doesn't take the finely tuned ear of a fox or coyote to figure out which one is the phoney.

I read how to do it many years ago and after a little experimentation discovered it really wasn't very hard at all and in the field it is DEADLY effective.

Me and another varmit hunting nut worked up quite a routine of various sounds that just drive varmits crazy. I've suckered many in literally to handshaking distance.

Besides being more effective, it's always with you and ready. Nothing to pack around and hope it works. Just pucker up and call.

Pecos,
I make a sound by puffing out my cheek to create an air pocket and then squeezing the air out by my back teeth. Sounds very much like squeezing a bunny. It works great on grey fox in heavy brush. But the volume is pretty low for calling open country.
I can also do a pretty good coyote howl, bark or yip and get em' to bark back. I have some good tapes of coyotes barking and yipping, they have different vocalizations to communicate different things. An aggressive bark seems to get an answer a lot.
But I still carry a couple CritR calls.

Critr - Try rolling your lips together (inward) like I guess you gals do with lipstick and then pull your lips TIGHT and practice sucking air in between these tightly clenched lips until you get the hang of making some high pitched squeeks.

It may be different with different people's mouth and dental structure but I get the best "buzz" off the left side of my mouth. (Remember, you are drawing air IN and not blowing it out.)

Once you get where you can make some squeeky sounds, then add your hands. With your hands pressed in various places around your mouth you can also tighten the squeal up better PLUS the hands act like the bell on an instrument and you can start working on PROJECTION. I got where all I use is my left hand on my mouth and can squeal loud enough that I've stopped coyotes and fox in their tracks at 300 yds. Varying and manipulating your hand around your mouth allows you to include all sorts of subtle variations in tone. You can make it sound like a real rabbit "bloodbath."

Once you get them in within 50 yds or less (assuming you aren't ready to shoot but just want to mess with their minds ) then change tactics. I pucker my lips OUT like I am going to kiss a frog's butt and then by drawing air in across this configuration, I can make a lot of different little "mouse-like" squeeks. Drives fox up the wall! This is where the game gets interesting as they will sometimes come right up and virtually try to sniff you. One more squeek and I think they would have been in my lap looking for dinner.

These techniques are easier to demonstrate than write about, but if you'll play with them until your lips get tired (about 15-20 minutes) a few times over a week, I bet a clever gal like you will do it.

I suspect the range of this sort of calling, once a person gets good at it, is probably 300-500 yds, depending on the terrain. Practice on the neighborhood dogs and cats. Generally they get REAL upset by this noise as well....even if they've never seen a rabbit. It just sort of pushes an instinctive button in critters. (I once called a big mule deer this way, believe it or not.)

Anyway, it's not hard to work out if you try. You'll make varmits do things you wouldn't think possible. Just don't get bitten...and I'm serious.