Never had any issues with my three... when we introduced a bed it was a full sized single bed so during the day naps i would start by reading a book then we would both lie down and if I closed my eyes and pretended to be asleep most times he would follow.... but be really asleep. I actually found it harder when he used a cot. There seems to be so many half sized "toddler beds' around on the market these days but I never really understood why (except maybe if you had space issues) you would use one in preference to a full single bed. I love the option of hopping in next to my toddlers in their bed.... they settle so quickly that way.

ETA: my youngest has just turned 3 and I still hop in his bed at night to settle him.