The rapid expansion of additive manufacturing (AM), particularly in fused filament manufacturing (FFF), necessitates specific standards for assessing the mechanical properties of AM-produced components. Currently, there is a lack of a dedicated standard for the geometry of specimens in 3D printing. This gap exists because 3D printing is characterized by a multitude of parameters, providing flexibility in choosing specimen geometry or parameters. This flexibility is a critical choice that can significantly impact the mechanical properties and the expected print quality. This article focuses on investigating the influence of sample size and printing parameters on the tensile properties and print quality of FFF samples. Through practical experimentation with polylactic acid (PLA) utilizing FFF, and supported by a literature review, the study sheds light on the crucial decisions related to geometry and printing parameters. These decisions play a pivotal role in ensuring accurate mechanical properties and offer additional benefits in terms of material and time savings, thereby advancing FFF technology. The study found that larger specimens conforming to ISO 527 standards yielded better mechanical properties compared to smaller specimens. Additionally, a 90° raster angle significantly improved both the tensile strength and Young's modulus of the printed samples.