Abstraction is the process of taking away or removing characteristics from something in order to reduce it to a set of essential characteristics. Abstraction process gives a way to see nature and how to extract beauty for design concept, The purpose of abstraction is to simplify nature, to extract primary logic for design expression. Through abstraction, the complex power of natural phenomenon can be stripped down, simplified studied and shifted into dynamic design possibilities. More observation practice here.
Make sketches of the reference images from different angles, try to capture essential characteristics.
Extrude lines to Tapering planes.
Extrude lines to sloped planes with cut-out. Keep fabrication constraints in mind, try to have every three-dimensional composition fit the defined design context.