Again Bravo73’s 5km and 1000ft cloudbase is a good start, but be very careful where this is taken from, especially when flying around hilly terrain. Check the elevation of the ground at least 10nm either side of your proposed track and work out what cloud base you can expect on your route by reference to TAFs and better still the last METAR at the nearest weather stations.
And then, most importantly, fly what you have, not what you expected! If is it worse - and it sometimes will be - turn back early. Have a diversion plan always in your mind. And if you really feel uneasy, just land somewhere sensible. It is very rare that a landowner will get upset when you explain. Better to work out when and where you can go when you’re on the ground with no pressure.