I was taught to treat clouds like upside down mountains. Having said this whilst I am only beginning to get a little better at keeping straight and level in the R44 after over 200 hours it still happens that when changing radio frequency or playing with the GPS, or worse still looking at my chart I hit a thermal or just move the cyclic a milimeter, and rise 100 feet, this I suspect if flying too close to cloud base could be the cause of many in indvertant excursion into IMC.