"tried so far" vs. "so far tried"

I have tried three strategies so far.

I have so far tried three strategies.

The two are equivalent.

Think of "so far" as acting as an adverb. Substitute now and you can say:

I have tried three strategies now.

I have now tried three strategies.

Same difference.

But if you are following it with a list, I would suggest you use the latter construction.

I have now tried three strategies: studying my rivals, cultivating new friends, and bribing public officials.

That way you put the noun that represents the list in apposition to the list itself.

Not an answer, but be aware of the (slightly obtuse) alternative reading, in the sense 'a trying experience':

You can only be tried so far before you lose your temper

or, the other way

He was so far tried, he decided to kill her