Let say I want to increase my credit limit, and I deposit big amount, do you think they will approve? What account normally to deposit? FD? If I have 50k FD can I ask for 50k credit limit?

I m not sifu but can share my experiance with u.
Other than u hav high income(but this is the fastest way to increase CL bcoz issuer always want u to proof ur income if u apply for increasing CL),huge spending,good repayment record and membership vintage might help u to get auto increase of cc CL.
Focus ur spending in single issuer and hold the cc for longer time(show them ur loyalty). I think u should get CL increase nearly every year.
When I was age of 21 few years back,my 1st cc CL only RM2k....   Today my lowest cc CL was RM45k and highest already 6 digits.

ahahahaha..not collecting anymore... wallet can't fit already...

infact, am going to cancel my AMEX Plat soon..since i got wat i want oledi...

dunwant to pay 800 anymore...

Then my opportunity cost is RM50 as my TNB bill every month is RM1000 leh...