Streetcar tracks are tricky and someone can get injured (or worse as in the case of yesterday's crash) if someone gets their wheels stuck in them. NOW Toronto covered the potential danger of streetcar tracks last week. But I'd like to just provide some basics of how you can deal with them better. It's making the best of a bad situation.
The key guideline is taking them as close to 90 degrees (at right angles) as possible so as to minimize the chance that your front wheel gets caught.
It's more difficult when you're riding alongside the streetcar tracks and need to cross them. Often it's because the right lane is blocked or the cyclist is trying to turn left. I will even turn a little away from the tracks first and then I can make a sharper turn across them. Make sure you slow down, signal and shoulder check first.
Or you can make an indirect left turn and avoid the stressful situations where you'd be trying to cross the tracks and watch out for fast cars behind you and coming towards you. It allows you to cross tracks at closer to 90.
Practice on a quieter street if you're uncomfortable. Toronto will have streetcars for a long time so it's best to focus both on education as well as on improvements to make them safer.