Check this thread:
Butollo call on Roe
Also, if you can, get hold of the Richard Prior CD on calling roe. It is some years old but still the definitive work on the subject. It is available from BDS and elsewhere:
Roe Calling with Richard Prior. Practice the different calls beforehand, not when you are out in the field. I spend car journeys in June and early July listening to the CD and practicing on the roe call, which can make it interesting if the phone is on "auto-answer".
From a personal perspective the main advice I would give is "don't start trying to call until you know for sure the rut is underway", as otherwise all you will do is educate the bucks to avoid the call. Resist the temptation to "give the call a try" and wait until you've seen definitive rutting behavior in your particular neck of the woods. The fact that the rut has started in the next county does not mean it's started where you are!
If you're not calling a particular buck that you can already see then make sure when you call that you have a good field of view all around. The buck that arrives may not be the one that you were expecting. I've had two bucks come to the call at the same time, which is logical if you think they are both looking for the doe. This also means try not to make any rapid movements when calling, as the buck that's coming might be behind you. If I can't see the buck I'm going to call then I will stand with my back to a tree and my rifle up on the sticks, so that if it appears anywhere in front of me I will be ready.
Remember what it is you are primarily mimicking - the call of a roe kid. Think about how a roe kid might move and breathe, and try to call accordingly. Don't squeeze the Buttolo like it's an old car horn bulb or a squash ball and emit the "Geschrei" alarm call unless you really mean to!
Also, when you call, don't give up too early. It is all too easy to call and then, 5 minutes later, convince yourself that nothing is coming. Bucks will hear the call from quite some distance, and they can take up to 20 minutes or so to get to you. Other times, of course, they will come charging in as though on a piece of elastic. The key is to give it time. Also, don't walk and call on the Buttolo at the same time - stand still dammit!!
As to weather conditions, I've tried calling in the morning, lunchtime and evening, on bright days and dull days, on warm days and cold days, and on normal days and when it's hot and humid (which is meant to be the best). Sometimes it has worked, sometimes it hasn't. I'm not a deer, so I don't know why.
Calling during the rut is some of the most exciting stalking you can experience and if you time it right, the adrenaline will be pumping - both yours and the buck's.
willie_gunn