Moving baby into sibling's bedroom - any advice?

[Dimples]

I am hoping that my 2 dd's will start sharing a bedroom in the not too distant future. DD1 is 18 months and DD2 2 months old - I hope to move her into a cot in the nursery at 4 months old when (hopefully) I'll cease feeding her at night. At present DD2 is in a crib next to my bed.
Would be grateful for any tips or pitfalls to avoid from those of you who have 2 little ones sharing a bedroom!
DD1 goes to bed around 7 and sleeps thru til 7.

Go for it! My two are now 3.5 and 5, and have been in a room together for the past 3 years. We put the baby in at about 4 months. There have been odd times when we've had to split them up, because of one crisis or another. But they actually prefer being together at nights than apart. My only tip would be as soon as possible do things together - tea tog., put them both in the bath together, jimjams together, and when appropriate bedtime together - it makes things a lot simpler.

My two are nearly 5 and 2.75 y.o., and they've been in together ever since dd was a few months old. We've found that it is amazing what disturbance a sibling will sleep through. They love being together, although now I can see the time approaching when ds will want his own space a bit more. They keep one another company, and are never scared of the dark or being alone at night, because the other one is there. Ds even takes his sister to the toilet in the morning, helps her take her nappy off etc. It's very sweet to listen to them . Another benefit is that when you go away on holiday or to stay with family or friends and they share a room, it's not an exciting big deal to be in together, so they tend to settle quite well.

On the downside we very occasionally have to go up after lights out and read the riot act, because they can rev one another up. But on the whole it's great.