I have made Strawerry and Crab Apple. I made the wine as normal with a starting sg of 1.095 and Red Star Champagne yeast and ket it go dry then added 2 ozs of sugar per gallon, stirred well and kept stirring while bottling. After 3 months of riddling I disgorged. At this point if you like dry youre done but if you want a sweeter sparkling wine then here is the next step.
Put into each of these bottles one ounce standard sugar syrup and one tablet of wine stabilizer (Crushed and dissolved potassium sorbate), and put these bottles into the freezer along with the wine. The stabilizer is essential to inhibit the yeast and prevent a third fermentation and possible explosions.
When the wine is cold enough, bring out one bottle of wine and one champagne bottle. After ridding the Sparkling wine of the sediment gently por the simple syrup in and top up if needed and recap.