Tomatoes I see you have a thread about.
A well established lavender can give you half a dozen cuttings when you prune it after flowering, remember there are many different varieties. It used to amuse me that people would often ask me to prune their lavender and add "It's a Hidcote." They would be very varied, I think 'Hidcote' and 'Munstead' are names which sell and are applied a bit indiscriminately.
I have a nice variegated box I take cuttings from when I prune it, they can take ages to strike, but usually do eventually, and I supply to a gardener friend. Aquilegia is another thing I have found grows well, looks good, and sells easily.
Welcome to the forum, do let us know how it goes if you realise any of these projects.