LED strips seem easy my ever lights. You peel the backing, stick it on the wall, flip the switch. Fast-forward two days: one end is hanging off the shelf, and the other end is half as bright as the first.
Start with adhesion. Even top-quality adhesive tape fails to bond if the surface paint is textured, the wood surface is dirty, or it's oily. Clean the surface with isopropyl alcohol and let it dry. Mounting clips or aluminum channels on rough surfaces work much better than tape alone, and the channels also act as a diffuser, softening the spotty look of each diode.
A dim far end means voltage drop. Somewhat counterintuitively, 12V strips lose power along their copper traces over long runs. Once a run reaches about five meters or more, the end starts fading. Power it from both ends, or go 24V - it handles distance much better.
Many buyers stumble on power supply sizing. To size a power supply: add up the total wattage of the strip, then choose a power supply at least 20% larger. A power supply pushed to full load wears out sooner and may even overheat.
Cutting is the next trap. Strips are made to be cut only at the marked copper pads, typically every three diodes. Cut elsewhere and that piece won't receive power. Reconnecting a cut strip takes solderless connectors or a steady hand with a soldering iron.
Consider where the moisture will be. Bathrooms, kitchens, and covered patios call for a silicone-coated strip rated IP65 or above. A plain indoor strip mounted near the sink won't last a season.
Last, choose controls with foresight. A simple remote adjusts color and brightness; an app brings scheduling and music sync. Certain RGBIC strips can run multiple colors at the same time on one strip - a nice touch for a feature wall, though an unneeded extra cost under the cabinets.
Draw up a plan, verify the measurements twice, and the install becomes easy.