1. I prefer my jam not to be too sweet and have the taste of fruit be dominant, but while cooking, taste the jam and if you find it not sweet enough add some more sugar.
2. I didn't blend the jam as I like to have bits of fruits in it, but if you prefer your jam to be of a more consistent thickness, then once your jam has reached the desired thickness take it off your stove (take out or leave the lavender blossoms, as you wish) and with an immersion blender blend until there are no more strawberry chunks.
3. You can use fresh or dried lavender blossoms, fresh ones may release a more intense scent, so use them sparingly.