Well IMHO "best" is a relative term. Best for what? In other words what are you trying to achieve? What type of practice is it that you want? A marketing consultant once told me you can prospect for gold using a firehose or a garden hose. If you use the firehose make sure you're prepared for the sheer volume coming your way.

The choices I see usually extend along different axis and also different demographic profiles. I personally think choosing your demographic is the most important. Why you ask? How many million dollar clients are there if you're targeting millennials vs baby boomers? Additionally you will need to communicate to millennials very differently than you will to baby boomers. Once you know that then you can determine the volume of both clients and assets you are going after.  Obviously it will take 10 $100k clients for every $1M client. Once you know "who" you are talking to you can then consider your options of how to talk to them.

As for how that's pretty straight forward and any decent advertiser can walk you thru the choices and cost.

So I'm 100+ words into this and haven't even come close to answering your question. That's because this isn't a simple question and anyone that posts "just do this or that" is wasting YOUR time. It worked for them but they aren't you in your market.