If I'm not mistaken from now until the release of Infinity War part 1 there will be 5 Marvel movies in phase 3 . (Captain America: Civil War, Doctor Strange, GoTG 2, Spiderman, and Thor: Ragnarok). *Ant-man is a phase 2 movie*. As we saw in the mid credits scene for Age of Ultron, SPOILER. Thanos appears and grabs the Infinity gauntlet and says " Fine. I'll do it myself." There are six Infinity stones that need to be collected, and with six Marvel movies in phase 3 up to Infinity war part 1 (can you see where I'm going with this?) we can set up 5 post credit scenes. What if after each movie the post credits scene is Thanos grabbing an Infinity stone and showing its power.
At the end of Civil War we are back at the Collectors destroyed collection. We see him walking towards a box, guiding someone along side him. As the Collector opens the box we see its the aether and it turns into a stone. We hear a voice say "your purpose has been fulfilled. I no longer need you". We see Thanos knock back the Collector and he grabs the Infinity stone, putting it on the gauntlet and kills the collector demonstrating the power of the stone. Now do to the fact we still do not know what 2 of the stones are i will be skipping Doctor Strange and Spider-man but lets assume he grabbed the 2 stones we don't know about in those movies. In Guardians of The Galaxy 2 the probably epic movie just ended and the credits have rolled. We are inside the nova corps. and we catch up with Glenn Close's character(Nova Prime). Out of nowhere there's an explosion and through the smoke we see Thanos come out. He uses the Gauntlet to kill whoever else is in the room and proceeds to grab Nova Prime by the throat demanding her to bring the orb, (from the first Guardians movie) and if she doesn't he will bring the destruction to the Nova Corps. and its entirety. She then does as ordered and brings the orb and adds it to the gauntlet, now holding 4 of the six stones. In a not so shocking turn of events he kills her using the gauntlet and laughs as he walks out of the hole in the wall and the screen goes black. Its the end of the year 2017 and we are now a movie away from Infinity War part 1. Thor Ragnarok came out and it turned out to be one of the best Marvel movies to date. The credits have rolled and we open up to this slowly panning shot of a destroyed Asgard. We see a defeated and battered Loki crawling on the floor of this demolished Asgard. He turns around to see a towering figure over him and we see fear in Loki's eyes. He goes on to say "Lord Thanos w-what a surprise what brings you to my oh so glorious kingdom". He's being his sarcastic self as usual. Thanos tells him "quit your games lord of mischief bring me what I seek". Loki gets up and brings him the Tesseract, when near the other stones it also turned into a stone. As Thanos adds the 5th stone to his gauntlet and looks to space. Loki asks "where is the final one Lord Thanos" to which Thanos replies " A planet plaguing the universe, the planet you were supposed to rule, this planet will be the beginning of my rule of the universe. Earth shall be destroyed." With the screen going to black and all we get is "Thanos will return in Infinity War"
This is what i hope for throughout the phase 3 movies just to get a taste of what's to come. If you have your own opinions or suggestions please comment them i would love to read them and discuss what you wish. Thanks for reading!