There's a few that don't usually pop up outside pretty good ones- dirty gifting, using attack/transfer only to control blockades, etc.

few tactics very experienced players use-
order delays
pro blockade(as mentioned above)
finding most efficient way to expand and attack(strategically)
using all cards to their fullest potentials
making most efficient attacks(mathematically)
taking 3 neutrals with 1 and 3 armies instead of 5
taking 4 neutrals with 1,1 and 3 instead of 6
using cyclic order to their advantage

Edited 5/18/2016 22:24:01

This game could have gone either way. We both used the strat mentioned. How did i do?
https://www.warlight.net/MultiPlayer?GameID=11204145