what I'm trying to say is (that)...
Well,
the point I'm trying to make is (that)...
think
Well, I I what I mean is (that)... (tentative)
suppose
What I mean is (that)...
(both direct)
What I'm saying is (that)...
All I'm trying to say is (that)... (informal)
Well, to be frank (strong, blunt)
frankly