The back-to-back Heineken Cup champions are in severe danger of failing to make the knockout stages when the competition resumes next month following their brace of December defeats to tournament favourites Clermont.
"From our perspective, we have to try and build some momentum coming into a busy next few weeks which will go a long way to defining the rest of the season," said Cullen, who is one of the side's few remaining front-line players available for action against Connacht on Saturday as Leinster struggle with Ireland call-ups for the two-day international camp in Carton House.
Joe Schmidt's side are on a three-game losing streak, and they suffered an embarrassing 34-6 humiliation the last time they faced Connacht.
"We need some big results and we need to try and get some more rhythm to our play," Cullen added.
"Against Clermont in the Aviva, we gave away too many kickable penalties and Morgan Parra kicked seven out of eight of them.
"Then, against Ulster, Paddy Jackson missed a few fairly kickable shots at goal, but Ruan Pienaar stepped up and kicked well.
" Dan Parks will punish any penalties we give away – he has such a high kicking percentage and has proven himself time and again over the years.
"So, we need to be more careful about giving quality sides easy opportunities to keep the scoreboard ticking over. These kind of games are won and lost over the finest of margins."
"We learned a few harsh lessons over in the Sportsground last time out against Connacht. I acted as water-boy that day and it was tough watching from the sidelines.
"They brought greater physicality to the game and they dominated us in that regard in Galway.
"We can't allow them to have that kind of an upper hand again. So, as 2012 draws to a close and we move into a new year, it's still all to play for. My first wish is that we get a few more points on the board.
"When we get a few more bodies on the deck that will boost competition for places, because we've been disrupted through the first half of the season and we have lacked a bit of fluency thus far. By the end of January we'll know our fate. We have a bit of ground to catch up on and, for us, that process starts this weekend."