Let me explain something about this, since I've got some experience with this.
Ok, so I have some old cuban cigars that are old and pretty much dead in my mind, half burned and its just not fun to smoke anymore. So I split them open, and got the leaf out. First time I did this I think I used too much, but damn was I fucked up.
Let me explain first time, and the times after that.
So, I've been smoking cigarettes off and on for a while, a year or 2 now, something like that, I'm pretty used to tobacco and I like getting my nicotine fix and rarely get any sickly feeling from it, except sometimes with cigars. Anyways, I had these old cigars, like I said, and I took the leaf from them. I ground up the leaf, moreso cutting it down with a razor blade, and then packed it with some weed into a small joint. Went out and smoked it. Damn did it feel good, went down smooth, gave a little tingly burning sensation in my mouth / throat, nothing bad. The weed took out all my urge to feel sick from the immensly potent tobacco leaf I had (full of nicotine, tons of it). Anyways, at the end, I felt a small urge to cough, and then when I was coughing, right after, it was small coughs, I puked right in front of me, thankfully didn't get any on me. But I experienced a nicotine overdose, common when you mix weed with tobacco, you take out the nausea that warns of a nicotine overdose. Anyways, its not too bad of a thing, you throw up, and your fine after. Ahh man though, I got wicked hungry after.
Anyways, after doing it a few more times and with just as much, if not more tobacco leaf. The joints, and blunts, they went down smoother, got awesome highs, ontop of the fact I noticed when mixing the potent tobacco leaf and the weed, my eyes didn't get red... odd, but thats what happened for me.
I'll tell ya this, think of a good nicotine buzz, like smoking a cig wicked fast while standing, then add in the relaxing, anti-nausea feeling, and you got the best high, well in terms of weed, my favorite is still crack and opiates, but weed and tobacco is pretty chill.
Cigarettes don't work too well with combining with weed to get the like huge nicotine dosage and the feeling of exhilaration that you get. Go to the store, buy a really good $20 cigar or something, like a Montecristo or Romeo and Juliet, or an Al Capone. Or if you want to be a bitch, get a pack of rum dipped Al Capone Cigarillos, those kick ass. Smoke a joint, then smoke the cigarillo, whole thing, will go down fast, being high makes me chain smoke. You'll get a decent feeling, but mixing the tobacco with the weed in the joint is awesome, make sure its good tobacco leaf in the joint, otherwise, its not that great, if anything at all.
Well, just my thoughts. Like for every amount of weed your doing, do 1/3 that in tobacco, and remember, good leaf. Mix it up good so you get it evenly distributed, and remember, put a filter, makes it way better, eases the burn.