Why so many guys claim "I dont do flat bench anymore, i might tear my chest", "i do only inclines", "I prefer dumbells" and so on.....why avoiding the barbell bench press?
As if they are going to end their "bb career". 
Anyway i did flat bench on Monday first exercise and it felt great.
Because they are too simple to do it right. It isn't all about the weight you can hang on the barbell, it is all about a form and patience to do it right and give the chest time to grow. On the other hand, that is just about impossible thing to accomplish if you are average amateur male BB:er, because no one want to look sissy. So we load all the plates what we can get our hands on to the barbell and usually use the weights so heavy, that we don't have any fucking way to move with good form.
Guy with the one of the best chest I have ever seen, ex Finnish pro Fathi Krishi, teach me the principle. He pointed out that even he was using quite moderate weights at the bench, he did have a best chest at the gym, which was crowded with the all the finnish pro's and national champions in every weight class you can think of. How is that possible? It is all about the form and using weight what you really can handle. He never do sets under the 6 reps and he always use a weight which allows him to feel the muscle all the way through the set. He was from Lebanon and a good friend with late Momo Benaziza who was also his mentor in this sport, and he was training with him in finland and scandinavia in those GP tours in that era.
What you do is stretch your chest completely before and after every workout, and do your set to the complete failure. You should warm up your chest before heavy sets with at least two sets of 20-30 reps, with the weight that allows you do just that, not 50 or 100 reps.That is called a pre- exhaustion, which is good and hardly used way of fool the muscle. You see, muscle doesn't have understanding, it is just a piece of meat, so it is quite easy to fool. It doesn't know if you are training with dumbbell's or incline bench, all it knows is exhaustion and stress. That's why, when you start with good worm up, you can beat the shit out of it without lifting so heavy. All you need is warm up, then you start with 75% of your one rep max and do set to the failure, at least 6 reps (use the spotter who really knows how to help with forced reps). Then another set with 85%, just like that one before, to the failure. If you need third set, you are complete asshole and you haven't done first two sets to the failure. With Fathi, his one rep max at the time was 280kg(617lb) which is quite a lot for a short guy(1,68m tall) You should test your one rep max every now and then, but that isn't the most important thing in your life. It is just a figure which you use to calculate your training weights. It will go up, if you do your sets in right manner, but most of all, you gain a full and thick pecks, with a lot of strength.
For the spotter, it is important to him to know how to do it: you don't grab the bar and yank it to the rack, but you use your fingertips under the bar and feel how much help you must provide to the last reps, if any, and you have to be fast if bencher reach his failure point. Then and just then you have to rack the bar, not sooner. Rule is that when bencher press upwards, the bar never moves downwards even a bit, but the spotter provides those drops of strenght through his fingers, feel if there is one more rep to come, and keep up the attitude of the bencher by asking for bencher one more rep if you feel it is coming, racking the bar if it isn't. For the bencher, you must have a trust for your spotter, and you must be willing to meet your failure point without any fear.
