I got rid of all the older players, and replaced them with youth. I sold Arteta, Koscienly, Djourou, Arshavin (first season - Jan), Rosicky (first season - Jan), Almunia (first season), Fabianski (first season), Squilaci (first season), Park Chu-Young, Marouane Chamakh (first season)
and put Diaby, Denilson, and Santos on loan (nobody would bid for them...)
I then invested in youth: A couple of regens (one with 188PA, the other with 182PA, as well as a few with 170-180PA), Kovacic, Felipe Anderson, Iker Muniain, Mbaye Niang, Carlos Fierro (free), Yaya Sanogo (free), Marc Munisia (free), Lorenzo Cristieg (free), Emre Can (1.5mil~), and, Hulk (29mil), Thiago Silva (29mil), Rene Adler (12.5mil) and Carlos Tevez (16mil) - although the last four weren't really young.
Now, the average age of my squad is 21.36 - and Bacary Sagna is the oldest player at the club.
I won the league in my first year, and, currently, I am on track to do the same again. With a back four of Bacary Sagna, Thiago Silva, Thomas Vermaelan, Kieran Gibbs, and Rene Adler in goal, we aren't conceding much. And, with van Persie, Tevez up front, Hulk and Gervinho on the wings, and Ramsey(who scores amazing long distance goals)/Wilshere and Song, we absolutely dominate our opponents defence.
Oh, and Van Persie was in the World Team of the Year, and Mertesacker(!) and Tevez were named amongst the subs. Ronaldo won the Ballon d'Or, while van Persie, again, came third. (Guess who came second... Messi)