I have been very patient and always look at the transfer market whenever I can for good deals, and now I finally have a team that if i wanted to I can use for the next 2-3 seasons without a single change and be very competitive. My advice would be to treat all positions equally, and when you see a good deal, go for it. I bought two 5* goalies using this process, and I only keep 1 on my roster, so I played each one, and kept the one with better form. I then trained the other one for a little bit and then sold him. I did this with a lot of my positions. In the end you get a team with good trainers who all have good form.