Yes I have taken each set to failure. With no guidance that's what I thought what was to be done. Why is this a bad thing? And then it seems unclear to me what is the best way to progress. Since obviously you can't tell how much your muscle has grown since a workout. What is the best way to determine and modify your sets or repetitions to that?
No, going to failure is not a thing that needs to be done. Far from it. That's more or less of a crossfit mentality, and I think it's harmful and dangerous at worst. Going to failure has it's place and time, but it should not be included on weekly training atleast on several exercises. The biggest problem to me is that you totally burn your nervous system. Going to failure means that you've put your whole body in a total overload and you can't produce enough force to get the weight up anymore. This is extremely taxing to the central nervous system, and can cause various recovery issues and execcive fatique. In a more daily basis, it can lead to an injury. When going to failure, your form will break, which is very bad if you want to train healthy for years to come. It can cause too much stress to the wrong places, like the spine, shoulders or pecs to say a few. When going to failure, you can't get the weight moving, so you will end up with your muscles suddenly losing all the tension and force and relaxing. That can have really bad consequence. Or the stress and tension might be too much for the muscle, and you will end up tearing and injuring your muscles. But that's the worst case scenario. I'm not saying it happens every time. Just something to think about.
Leave one or two reps in the tank. It's far safer, better for recovery and better for your technique. It takes practise to know when to stop, but you'll get it eventually.
The term progressive overload is used alot these days. If we want to explain it simply, it means we try to increase the workload from last cycles efforts in either one of three ways: 1) Increase weight 2) Increase reps 3) Increase sets. Then there are minor progressions like decreasing rest time or messing with time under tension. But that's the basic. Everyone here on ExRx practically uses progressive overloading. I usually add reps, then sets, then weight. Say, going from 3x3 to 4x5 and then increasing the weight or something like that.
Okay, I will incorporate these large compounded movements into my workout. It just seems as if I won't have as successful lifts after for the smaller muscles. Wouldn't you say so? If I was to do bench press followed by tricep curls obviously I wouldn't be as efficient on the curls.
Why would you need to be more efficient? If you did tricep curls first, you obviously wouldn't do so well on bench. You want to get lean, so big compound exercises are the best way to go. Why? First off, you work the most muscles on big exercises. Like in bench, you get your triceps, shoulders, back and chest all activated. Or like in Squat there's your whole lower body plus back, core and arms working for you. Secondly, since it has so many motor units and muscles working hard, it burns the most fat and builds the most muscle. You get leaner and stronger. There relatively is not much smaller muscles you can't work with big compound exercises, so don't worry about that. But if you want, that's what accesorial work is all about. If you feel the need, you can do sets of tricep work or shouler work after the big exercise. No-ones stopping you there. Just keep it reasonable and simple.