To avoid double taxation, you have two options:
-Claim the FEIE (Foreign Earned Income Exclusion). This allows you exclude foreign earned income from US taxes, up to a certain amount (~100K USD).
-Use FTC (Foreign Tax Credit). As you mentioned, you can get a credit for every tax dollar you paid to CRA that you can use for your US taxes.
In situations where you are in a country where the taxes are generally higher (like Canada), the second option is usually the better one. This is because you will often have more than enough tax credits to offset the taxes owed to the IRS. Note that not all income is covered by the FTC. There are some cases where the IRS has first dibs on the income tax. In those cases, you pay the IRS first and then get a tax credit to use for CRA. It sounds like you already know most of this
The other benefit of the FTC is that any unused credit can roll over to following years for up to 10(?) years.
Most residents of Canada in our situation use the FTC.
Get a reputable crossborder accountant. This is key. The accountant can file both Canadian and US taxes. the accountant will first prep your Canadian taxes (assuming you reside in Canada and your income is mostly Canadian based), figure out how much tax credits you have, and then use it to prep you US taxes. The accountant also see which income must be taxed by the US first and then update your US return and Canadian return appropriately.
Note that there are a LOT of tax traps to be aware of that can really complicate things. For example, you need to keep in mind there is a sweet spot in regards to the amount you can contribute to your RRSP. Stay away from TFSA and RESP. Stay away from any mutual funds and ETFs outside the US that is not in a recognized registered account (like RRSP). If you own your own business in Canada... yikes.
