I tend to play relatively historical within limits, I try to avoid getting involved in land wars in Europe as Britain for example, but I don't hold back if someone declares war.

As Prussia, I usually start off being aggressive against the German minor powers and this will almost always bring a larger power to war (Saxony & Poland, Bavaria & Austria, Hanover & Britain) and then I proceed to take territory away from the first two and get colonial or tech concessions from Britain, as invading the home isles would be just a bit ridiculous.

As Spain or France on the other hand, invading Britain is on the cards, as this was something they had wanted to do several times. As France I attempt to expand east as they did historically and as Spain I worry about the Dutch, Italy, North Africa and North America... etc

I usually wont limit myself too much, but playing with a bit of historical flare can be quite fun.