In a medium saucepan, combine the milk and cream. Place over medium-low heat and cook, stirring occasional so a skin doesn't form. You want the temperature to reach 170°F.
While heating milk/cream mixture, whisk egg yolks in medium bowl. Gradually add 2/3 cup of sugar and xanthan gum and whisk until mixture is thick and pale yellow. Temper egg yolks by slowly pouring 1 cup hot milk mixture at a time, whisking constantly. Return egg yolk mixture to to saucepan and place over low heat. Cook, stirring frequently with a wooden spoon until the custard reaches a temperature of 185°F. Pour the mixture through a fine-mesh strainer into a clean bowl and cool to room temperature, stirring every 5 minutes. Once room temperature, cover and place in refrigerator for at least 4 hours or overnight.
In a medium saucepan, add strawberries, 1/4 cup of sugar and lemon juice. Let sit for 15 minutes.
Place saucepan over medium heat and cook until strawberries are softened completely and the syrup just starts to thicken, about 10 minutes. Remove from heat and let cool to room temperature. Transfer to airtight contain and place in refrigerator for at least 2 hours or overnight.
Add 3/4 of the strawberry mixture to a blender or food processor, saving 1/4 of it for later. Add half of the ice cream base and vanilla extract to the blender and blend until it is fully incorporated with strawberries. Mix in remaining ice cream base.
Pour mixture into ice cream maker and mix according to manufacturer's instructions. (every ice cream maker will be different. Ours takes about 20-25 mins) With 5 minutes left, add remaining strawberry mixture to ice cream machine. Once desired consistency, pour ice cream into a container and freeze in freezer for 4+ hours to get a desired consistency.
Use the Best Ingredients - when making ice cream you want to use the best ingredients possible so use free-range eggs and organic milk and cream. Also use high quality products when it comes to added flavorings like vanilla or chocolate. Never use imitation vanilla.
Don't Cut the Fat and Calories - ice cream is not the dessert that you should be cutting the fat. It depends on the high-fat content to create a creamy texture. If you go lower fat, it will cause an icy ice cream. If you're on a diet, just have a smaller scoop!
Add Extract at Right Time - if you add an extract or alcohol while the custard is too hot, you won't get the actual flavor as it will cook out slightly. Just wait until right before you pour the custard into the ice cream maker to add it.
Chill the Custard - you don't necessarily need to chill the custard overnight, but you want to chill until it is as cold as possible.
Use Frozen Bowl - make sure your ice cream bowl has been frozen for at least 24 hours, otherwise you aren't giving the ice cream a great chance of freeze.
Start Ice Cream Motor First - do not pour the custard in the frozen bowl before starting the ice cream maker. It will start freezing upon contact. You want the motor running and slowly pour the custard in.
Add Mix-Ins at the End - never add your mix-ins at the beginning of the process. You want to add them when it looks like there is about a minute left in the churning process.
Don't Overchurn - always error on the side of caution when it comes to churning your ice cream. You do not want it to be hard. Remember it will continue to freeze once you place in the freezer.
Keep It Creamy - homemade ice cream can turn hard as we don't add preservatives, however Xanthan gum or a couple tbsp of vodka will help keep it creamy.