If you’re flying into Switzerland, you will probably want to get to Lausanne from the Geneva Airport (GVA).  The train will easily take you from the airport to Lausanne in 42 minutes and for a reasonable price.  The train station is on Place de la Gare, which puts you pretty much right between the Ouchy shore and the Cathedral at the top of the hill.  If your hotel happens to be on Place de la Gare, then you’re in luck since its one of few streets in Lausanne that doesn’t involve a steep hill.  

From the train station, those with lots of luggage will probably want to take a taxi to your hotel, as depending on where your hotel is located, you may have to go a fair amount uphill (or at least take the bus) – it’s worth it to avoid the hike up Rue de la Petite Chene with rolling luggage).  If you’re staying near the Ouchy shore, the bus also can take you downhill as well.  

For those planning to arrive by car, Lausanne is connected to Geneva and the north (Bern-Zurich) by the A1 motorway, and to the Alps by the A9 motorway. Swiss motorways and roads in general are very good, using the motorways require a 40CHF windscreen-sticker which can be bought when entering the country (and will already be included with every rental car). Beware however that like many other Swiss cities, Lausanne has a policy of (strongly) encouraging the use of public transportation: private parking in the city is very expensive and often for a very limited time (1 or 2 hours maximum, subject to hefty fines). An option is to use the "park & ride" offer by parking in the designated parking areas in the outskirts: the parking fee includes a one-day pass for downtown public transportation.  

The other option is taking a lake boat from Geneva to Lausanne, which is a nice ride across Lake Geneva/Lac Leman, though it is less convenient. The boat takes you to the Ouchy shore, near the Chateau d'Ouchy.