Casual thieves will try to defeat the ignition/steering lock and either ride off with it or ramp it onto the back of a pickup.
Professional thieves will bring a couple of bars of rebar and a buddy or three, pick up your ride and haul it into a truck.
Prefer covered/underground/garaged parking over uncovered/lot/street parking.
If fewer people can see your motorcycle, fewer people will be tempted to make off with it.
Most thefts occur between 11 PM and 6 AM when there aren't too many people around; a well-lit, high-visibility parking lot won't deter a seasoned criminal if there's nobody around to see him.
If you can, also park between obstructions, in low-clearance areas... anywhere it would be difficult to maneuver a pickup or truck to load the bike into it.
However, be careful not to park in front of access doors, in striped zones (e.g., next to handicap spaces) and near machinery.
Granted, your bike will be perfectly safe in the impound lot....
travel.stackexchange.com/users/None/
Friend is currently riding from London to Mongolia.
His method (he's in Uzbekistan at present) has been to find hostels / hotels with secured off street parking, meaning he can not only put his own locks on, but it isn't accessible to opportunistic thieves who pass by.
So far, so good!
travel.stackexchange.com/users/101/Mark Mayo
I spent eight months traveling from Arizona to Argentina on a 2001 KLR 650r.
I used a 15 foot Python cable lock to secure my gear (helmet, jacket, etc) to my bike but to also loop it through the wheels and connect it to a permanent structure.
I never had problems finding a place to park my bike.
I always found a way to get it off the street for the evening.
Ride your bike up steps into hostels or hotels.
The less developed areas you travel through, the more inclined people will be to let you do it.
Greatest tip for securing a bike is to have a "crappy" bike or make it look like it's not valuable.
Keep it dirty and keep it in a public place.
Last word, the world is a safer place than you might think.
Have a great time.
travel.stackexchange.com/users/1877/AtlasRider
Easiest and cheapest in my opion: Buy a couple bike locks Put them around each wheel.
If someone really wants to steal your bike they will (even if it's in your hotel room), this should deter most people.
travel.stackexchange.com/users/9/silent1mezzo
I went on a 5,000km bike ride around western europe, and used disc locks, and a chain(ish) to lock our 2 bikes together.
Off street parking is good as well, prevents anyone from seeing it from the road.
I didn't find anywhere that would let you bring a motorbike into the room.
travel.stackexchange.com/users/243/Rory
The OP doens't mention which country, or the size/type of the Motorcycle.
I've been all over North America on a Honda Valkyrie Interstate - which is a pretty big bike -
and I've never had a problem with security.
The usual things I've done at night have been: put the bike where the front desk can see it, up on the sidewalk near the front entrance, in the parking lot
In all cases I generally put it under a cover, which keeps the elements off and deters casual snooping.
YMMV for other countries, but in North America I wouldn't be too paranoid about securing a big bike.
travel.stackexchange.com/users/1856/Tim Kuehn
Presumably, your question is about USA?
If so, put a bike cover on it and park it
right by the reception area and ask them to be on the look out.
That's really all you need.
Anything more is paranoia.
A good motorcycle lock that can't be easily cut with bolt cutters in less than 30 seconds is very expensive and impractical because of the weight and bulk.
A crappy lock might make you feel better, but it's pretty much useless.
Bikes are simply too easy to steal.
travel.stackexchange.com/users/1885/Witold
If more than one bike is involved, chain the two bikes together.
It doesnt avoid the problem but it eliminates the options of lifting the bike onto a truck.
travel.stackexchange.com/users/47342/user47342
I'm mostly thinking in terms of theft prevention.  I have heard solutions from, "Keep her chained in the parking lot," all the way up to, "Get a ground floor hotel room and ride/push the bike inside the room."  What measures can one take to keep a motorcycle safe during a road trip?
What measures can one take to keep a motorcycle safe during a road trip?
travel.stackexchange.com
<road-trips><security><motorcycles>
travel.stackexchange.com/questions/305
travel.stackexchange.com/users/33/Raj More
Park your bike on the sidewalk outside hotels and hostels where the front desk can see it, and make sure it is properly locked. Use a bike that is not too attractive to criminals. Riding your bike up your hostel's stairs, parking it it near to the entrance where it is visibile to the front desk or putting pad locks on each wheel are a few security measures you can take to prevent your bike from gettting stolen whilst you are on a road trip. However, it is advised to use a motorbike that isn't of value when going on a road trip.
Riding your motorbike up hotel and hotel stairs or parking it near the front entrace where it is visible to the front desk are ways to prevent your bikegetting stolen. Going on a road trip with a motrbike that is not of value will prevent it from being stolen.  The cheapest option is  to put locks on the wheels to prevent your motorbike form being stolen. If you are tevelling with more than one bike chaining them together is an ulterior option.