The tubes and cylinders are probably easier, the organic shape is a bit trickier. When you have insufficient, bad quality reference images, you can start with placing only the edges you can see in the reference, only when you can guess their position in 3d space. Then you have something to work with and can start filling the spaces between them with surfaces constantly adjusting everything as needed when you compare your result to the reference:
I would use F2 add-on for quick filling and LoopTools add-on for relaxing edge loop segments. I would simply keep extruding single vertex to make the lines. Subdividing edges to get a vert in the middle is useful, also using Bevel for vertices(Ctrl + Shift +B) can be a quick way to place multiple vertices in a smooth curve. The idea here is to keep in mind that this geometry is for Subdivision modifier(you could also just add the modifier to see the result while working), you should have as little geometry here, as possible, only enough to hold the forms, because the fewer points you have the easier it is to adjust them. I would use edge creasing(Ctrl + E) and Subdivision Surface modifier to smooth and add resolution to everything then I would bevel the resulting sharp edges with Bevel modifier. It's easy to use edge bevel weight as limit for the modifier because you can set edge weight at the same time you crease the edges.
That's the reference initially provided:
