I will likely fly RT once per year:

LAX-HK via CX or AA once per year
LAX-SING via CX
LAX-LHR via BA
LAX-GIG via AA, Tam or LAN

These are generally biz or 1st class expensive tix ($3-6K RT).

I'm a newbie when it comes to figuring out the best strategy for accumulating miles/points. What's the best way to purchase these tix to accumulate the most miles?

- My SPG Amex card
- My AAdvantage MC card
- Do I sign up for a BA card and a CX card, and purchase the BA and CX tix this way?
- Other?

For example, is it better to purchase an AA flight with AAdvantage MC or with SPG so that I can transfer 1.25x miles to AA for redemption on AA, CX, LAN, etc?

In case it's important, I'm most likely to redeem points LAX-GIG on AA, TAM or LAN for family vacations.

Thanks for your feedback

It is certainly better to purchase AA flights with the AA card. 2 miles > 1.25 miles.

Given your estimated spending, have you considered the Amex Premier Rewards Gold? 3x points on airfare plus 15,000 bonus points every year you spend $30k. The relevant questions are whether you can stomach the $175 annual fee and whether the Amex point transfer partners suit your needs.