Musée du Louvre is massive. It's enormous, the collections are beautiful, and there is no way a visitor can comb through everything in a single day. This is what makes the Louvre so great- a visitor can return again and again and see different things. It can be touristy but it is also the most incredible museum we've been to, to date.
First, the Mona Lisa. Every first-time visitor here wants to see the Mona Lisa so everyone's hurdle is that everyone else also want a glimpse of her. The painting is small by all standards of other famous paintings at the Louvre and the Mona Lisa is encased behind a glass. There is even a barricade so that the closest anyone can get to the Mona Lisa is a few meters away. Unless you are willing to elbow your way through the sizable crowd, you will most likely be raising your camera in the air hoping to catch a good shot of the painting from afar. So how do you get around this? 1) Get there early, and 2) use the Porte des Lions entrance on the southwest wing; look out for the large green lion statue. The Porte des Lions entrance brings you right into the Denon Wing( the Mona Lisa is located in this wing). Avoid the Pyramide entrance which is what all other tourists use. We arrived at the Louvre right at 9am when it opened (lucky for us, the Westin was less than a 10-min walk away), entered through the Porte des Lions entrance, went through a quick security check (no lines!), and made our way to the Mona Lisa. There were people already there at the painting but it was a breeze to get a perfect view of the painting.
Pre-buy the tickets online and collect them at any FNAC outlets in Paris before your visit to the Louvre. This will save you time from standing in line to buy tickets at the museum itself. €12 admission to the permanent collections is a steal considered that it's a world class museum.
We spent about 3 hours at the museum on our visit and planned our trail according to the collections and exhibits we wanted to see specifically. I suggest you do that too because the museum is enormous and if you walk in aimlessly, you will easily get lost and end up missing important collections or the exhibits that interest you. We downloaded the museum map onto the iPad which helped us navigate the museum. Visiting the other exhibits and collections on a second trip to the Louvre is on our list.