Proper termination is what keeps signal loss low. The process is the same whichever method you use: strip, cleave, then connectorize or splice.
Fusion splicing joins fibers with a heat arc for a permanent, low-loss joint. Mechanical splicing aligns fibers in a small fixture and is quicker to set up for fast repairs and small jobs.
Whichever you choose, always inspect and clean end faces before connecting. A dirty or damaged connector is one of the most common causes of problems on a fiber link.