You do not need to see the ground fetures, just fly headings and times until a decent feature is available, bearing in mind any high ground in the area.
A useful thing if you're up against what you hope is only a small patch of poor vis is tuning an ATIS for an airfield you hope is on the otherside, or failing that asking whoever you're talking to (london info etc) for the latest weather at a specific airfield. Note, this is only where the vis is 3-5k where you can legally still fly but not perhaps navigate by feature crawling. If you're up against very low cloud or a snowstorm, always best to turn back.