Do yo ugradually HR before hitting an uphill ?
 

If you are cycling at 'dawdling' pace and then encounter an uphill, do you increase your pace slightly to get the heart rate up before you start exerting effort for the uphill (so that your heartrate doesn't go from dawdling mode to high mode too quickly) ?

i speed up to get some momentum up the hill, especially if it is a tiddly hill. sometimes i can get over the bump with this momentum.

No, HR doesn't enter into it. If I feel like going hard, I go hard, if I feel like going easy, I go easy.

Only if it's a short hill I want to get over quickly... If it's a long climb I try to keep my heart rate steady so I can last the whole climb and not just burn out at the top.

Depends on the ride. A lot of times when a hill is approaching on a group ride, I will attempt to conserve as much energy as possible and get my HR down as much as I can so that I have a little extra buffer when the hill arrives and people start popping out of the saddle and hammering up the hills. If I am in front pulling right before the hill, I just keep the HR up where it normally is and set the pace for the hill. If I'm riding solo, I don't really think about it much. I just ride steady.