I was silver 3 like 5 days ago, but I fucked steam rolled through the game and reached crystal just like that lol
I have a trophies based base, I also spend all of my gold and elixir before i go to bed everyday so that no one invests too much in attacking my base, if anyone does, then it's free trophies for me. Also, I started playing this game 4 months ago. Basically, I attack enough everyday until i get at least +1 Million of each gold and elixir :>
TH7 is similar to TH9 to be honest, the only difference is the level of your troops. Back in TH7 I used to only build archers and attack other bases resources that are on the outside not the inside - most of their resources is also on the outside.
But, in TH8 I changed that to 16 Giant, 14 Magician, 7 Wall breaker, and the rest are Archers - and still using that now in TH9, only higher level troops. It costs around 75k or something. With the two lightening spell and healing spell It's like 135k I think. But, from the other hand, I only go for bases that has at least 200k of each Gold and Elixir.