Using an established site/domain to avoid the "sandbox"

Ok, basically I've wasted alot of time buying domains, creating websites and building backlinks only to have myself get kicked off the top 10 in a matter of a few days. When I say "kicked off", my site basically disappears from the top 10 and is nowhere to be found for the term I'm trying to rank for, but is still in google when I search up the domain. I've read many other threads where others have had the same happen to them, and it apparently takes a few months to start climbing up the rankings again..

Well, I've just been thinking of ways to get around this. Just wondering, what if I used an established site instead? I have a 2 year old website that does really well in Google. Can I just create subdomains off this site and do the usual social bookmarking, sig links, etc. to get myself up to top 10, or would I get the same treatment from Google (get kicked off top 10 in a few days) regardless of the fact that I'm using an established domain/site as a backbone? Would I last longer in top 10 with the help of my established site?

Any advice on this would be very much appreciated.

Thanks