A visual approach procedure doesn’t take any obstacles into account - that is why good situational awareness is essential. Personally for visual approaches I don’t really follow VNAV (I like the idea of having VNAV guidance) however at the end of day a visual approach is what exactly it is - You need to fly it by looking outside of window as well as staying clear of any clouds and maintaining separation from any obstacles visually.
If the weather is not reasonable or if visibility is significantly reduced at destination then consider using a instrument approach procedure, if still going ahead with visual approach then my general rule is I need to see the ground and runway by 1000ft above ground level (Normally circuit height in most cases) if not then execute a missed approach and climb to minimum safe/sector altitude.
