When I first started triathlon it seems I heard a lot about sighting and I thought it was going to be something you had to work at. Now after doing an Olympic and a Half Ironman I can say that I don't really understand how anybody spends anytime focused on sighting. Most any race has pretty huge bouys that are hard to miss, and if you are a middle of the packer like me there are plenty people around to keep you going in the direction at all times.
For me the big difference is form. I got to the point where I was swimming 1000m in the form of 10 x 100. Then I watched a couple form videos online and literally two workouts later I swam 1600m non stop with ease.
So I would say visit a couple sites like
www.swimsmooth.com or
www.youtube.com/tiswim and find what works for you. There is no perfect form for everyone, each person is different. For me I follow the Total Immersion style more than anything else because I hate kicking. I have never been a strong kicker and TI focuses more on the kick simply being about rotating the body than it is about floatation or propulsion. So it works perfectly for me. That style of stroke feel effortless and easy to me.
I would spend a good week focusing on form and finding what works good for you.