Probably the most creative space tactic I ever read was in the (otherwise undistinguished, IMO) book "Europa Strike". It goes like that:

Evidence of extraterrestrial intelligence is found on Jupiter's moon Europa while, for unrelated reasons, tensions mount between US and China. An armed American spaceship is dispatched to Europa, while another is orbiting Mars. A Chinese ship launches, seemingly toward nowhere in particular. Few days after launch it detonates a fusion device, in a 100 megaton range, in empty space. No one in US can figure out the purpose of that, except possibly as a "message" -- demonstration of power. ("What happened to sending messages by e-mail?" grumbles one US Marine.)

What the Chinese spaceship actually did was fire an enormously powerful railgun, twice. The fusion bomb was a smokescreen -- the sleet of charged particles completely masked the EM pulse from firing the gun. Inert railgun projectiles are easy to get out of the way -- if you know they are coming. But no one does.*

One swarm of projectiles is aimed at Jupiter -- or rather where Jupiter will be some months later, when first American spaceship arrives. Needless to say, it is timed to arrive simultaneously with the said spaceship... and the projectiles have enough self-guidance to hit it. The other swarm is slower, and is aimed to where Mars -- and the second American ship, -- would be at that same time. Chancy, of course -- if that ship leaves Mars orbit in the intervening two months, it is safe, but the Chinese take this gamble. And the beauty of this is that if for whatever reason Chinese Politbureau decides to call off the attack -- no one will ever know it was underway! Just send a very short radio code to the projectiles, ordering them to miss their targets. And if they are needed, the attack is undetectable and unstoppable. Europa-bound swarm moves at over 100 km/sec, the Mars-bound one at about 25 km/sec. The course correction occurs within seconds from impact, and until then they are black, cold and silent.

*This was one of the things Heinlein got wrong in "The Moon is a Harsh Mistress" -- short of a nuclear detonation, there is no way to hide the EM pulse from a railgun. Manny and company could never keep their second catapult a secret.

__________________
Fiction has to be plausible. Reality is under no such constraint.