I already have HDFC business money back LTF card. I want to apply for every LTF card available in the market either directly or using any kind of referral or tricks. Can anyone here help me with this?
If you're talking about entry level LTF cards, they're easy to get anyway, no tricks needed. Few are conditional LTF like HDFC Regalia (spends based and some other conditions are there). For affluent/UHNI cards, you need to have exceptional TRV maintained with bank. No hidden tricks are there.
As I just checked the cards you're having right now, they best you can do is not to rush at all. Take it slow. If you're a salaried person check whether you're qualifying for HSBC Platinum or not, if yes, get it. Then give a break of a year...