Look, I know what you want - you want bigger biceps. fine, who doesn't? But you are not going to get them by doing endless sets of curls. You need to stop thinking about your biceps as if they were some magical muscle that exists separate from all the rest of your body.
Unfortunately for those of you who are in love with your curls, it may be time to step away from them. If you really want your arms to grow, you may want to stop doing biceps workouts altogether for a while. I know this sounds crazy, but bear with me here for a minute.
Why should your arms grow by themselves? Sure, you may be able to force another quarter inch out of them with lots of volume, and progressive weight increases, but at some point progress will stop, regarless of how many bicep workouts you do, Aside from Tom Platz's legs, it is very hard to make one body part grow out of proportion with the rest.
Who has big arms? Big people, that's who.
If you really want big biceps, you have to put in some time under a big bar, with a lot of iron on it. Get into the power rack and concentrate on your squats and deadlifts for 2 months. (I know, horror of horrors!) Eat big, get big, and you will see the gains in your arms size follow. Show me a guy with big arms, and I will show you a guy with a big back, and more than likely, big legs as well. He didn't get that way by doing endless sets of arm exercises.
The most commonly used rule of thumb is that you can gain an inch on your arms for every 20 pounds of muscular bodyweight. I know, that is a lot of weight. But if you will concentrate on the big lifts for a wile, what you will find is that your bodyweight will climb. If you can manage to eat clean at the same time, you'll see your bodyfat percentage drop at the same time.
If you can manage to gain that 20 while dropping even 5 pounds of fat, it will make a very dramatic difference in your appearance. Your arms will grow right along with the rest of you as well. If you gain less, you will see less arm growth, but you will still have some. The growth you do achieve will be in proportion to the rest of your body and if you managed to lose some flubber, your arms will look harder and stronger.
So what would this workout routine look like? Simple, but hard.
Bent over rows 4x8
Same as Mon
Mon - repeat cycle, alternating workouts.
Ok it looks way too simple, right? But if you have the stones to pile on the weight and do it, you WILL see results. I know, because I have done it. Once your foundation is bigger, you can go back to doing your regular bicep workouts, and curl until the cows come home.