We flew from the UK into Venice Treviso on a low-cost airline. We were having a few days in Venice at the end of our break at Lake Garda, so this was the best option for us.
There are plenty of flights and airports closer, but it takes about 2 hours to drive from Treviso to the southern edge of the lake. The roads are toll roads, easy to navigate on and simple and pleasant to drive on.
At the lake itself, we used a mixture of our hire car and the ferries to get around.
Ferries are probably the best way of getting around the lake. The bonus is that you can soak up the sun while gazing at the dramatic scenery drifting by. As you travel north on the lake, you can see just how dramatic the lakeside mountains are and see so much more than you would from the road.
The car ferries offer good value for money. They are not as quick as some of the other boats, but they are the cheapest and allow you to take your car over the lake if you wish. There are 3 decks - the bottom one for vehicles, the middle deck has seating and toilets and the top deck is open.
The high speed ferries are a great fun experience. You get whisked over the lake at high speeds. They only tend to stop at the largest lakeside towns.
You can buy tickets at any major port. The kiosks close to the landing stations sell tickets and have timetables. Always make sure you can get a return boat back in time. Many boat services end by 5 or 6 in the evening, so plan ahead and do not get stranded.
Travelling along the lakeshore by car is also a fun thing to do - there are many tunnels to travel through as you go north through the mountains. The most recent James Bond film was made in this area, and they used some of these tunnel scenes in the movie. The only downside to using the car is it can take quite a long time to travel a relatively short distance. The towns do tend to be a bit congested and the traffic is slow moving, so plan for this before you set out.