Real painting, of course is fine, but it requires serious effort and talent.
In Photoshop you can use fake art filters to convert flowers to look out painted. Even imported clipart flowers may bend under these filters. There are some filters in PS included.
Third party plugins can be found. There are free ones and commercial. I have tried Topaz Labs stuff (Simplify, Restyle). Frames are available as clipart (both photos and vector graphic) At least texts are useful to be started in vector graphics program (Illustrator ot thatlike) Metallic glow is available as effect. Slight feel of oldiness and weariness is best achieved in photoshop - filters again. Consistent colors in Photoshop, too.
This design probably takes a day or more to be replicated or adapted into a new design well enough to be shown. The replication job also needs some serious artistic talent. Bare skill on available tools is a must, but it's not enough. Without artistic talent you simply do not make things consistent and not seeming like they are in a wrong place.
ADDENDUM: An example of fake art filtering and the original, too. Details are simplified, blue background and some twigs are swept off to make space, painted strokes are applied and a canvas texture is added.