Political stability
Changes in government regulations can impact on property values.  Countries affecting change to promote foreign investment will likely positively affect values.

Economic stability
GDP, population growth, currency exchange and trends in the real-estate market are all sound indicators of what can be expected in the future.

Ownership eligibility
Ensure you’re aware of the legalities and transparency of ownership in each country.  Check for any favorable exemptions for foreign investors.

Tenure
Tenure of ownership is different in each country and generally varies between freehold (outright ownership) and varying terms of leasehold ownership.

Forecast or guaranteed rental return
Developers are packaging their product to be as competitive as, if not more than, other asset classes.  Check that forecast returns are realistic and achievable.  If returns are guaranteed, check the developer can warrant payments.

Financial leverage
The ability to obtain mortgage finance will multiply your return on equity.  Check there are financial institutions either locally of offshore that will be able to lend on the property.

Ancillary purchase and disposition costs
Each property may have different rates and types of taxation, management fees, sinking fund, administrative and legal costs when purchasing selling and throughout the duration of ownership.  Ensure you understand the entire commitment of funds required for an acquisition.

Developer and consultant track record
Particularly important when purchasing off-the-plan; investigate the developer’s previous projects as well as  consultants that have been contracted for the project, such as architects, construction company, management company and engineers. 

Construction period
Depending on your motivation for investment, longer periods of construction will generally allow for market growth and, in turn asset appreciation.  A flexible payment schedule that allows minimal upfront deposits prior to completion can benefit the speculative investor.

Payment schedule
Payment terms that allow minimum deposits upon purchase and the majority of payments at the end of construction will alleviate the interest-opportunity cost of zero returns during the construction phase.

Packaging
A good offshore investment will require you to do as little as possible in terms of management of the asset.  Ensure you have access to necessary furniture packages, lettings, management, payment of rent and avenues for disposition.
  ( Adopted from Luxury Properties Magazine.)