The Tayside club returned to winning ways last weekend when they ended a seven-game streak without a victory by beating St Mirren 2-1 in their William Hill Scottish Cup last-16 tie.
United had lit up the Scottish top-flight earlier in the season when they gained widespread plaudits for their attractive style of play.
Now McNamara wants to see his side rediscover that type of form as they aim to make it back-to-back wins when Killie are the visitors this weekend.
He said: "We want to get back doing what we were doing earlier in the season.
"It was important we won the St Mirren cup tie last week because it helps confidence.
"The lads deserved it for the way they played and we know what they're capable of on their day.
"Now it's a case of trying to build on it when Kilmarnock come to our place.
"They're never easy games against Killie but we're looking on the positive side of things and focusing on what we're good at.
"We got a lot of praise earlier in the campaign for our play and results which shows we can do it.
"Every team goes through a not-so-good patch and hopefully we can kick on now in terms of results."
United defeated Allan Johnston's men 1-0 at Tannadice back in October but knows they will be all fired up for this occasion
He said: "Killie played well here the last time and won't want to lose again.
"They've picked things up recently and always try to play football.
"They have some good players in their side so we know what to expect.
"As far as we're concerned, we should be more relaxed going into this game.
"There was a bit of pressure with us being on the kind of run we were on before the St Mirren game.
"So I would expect the lads to feel good going into this game.
"We want them to enjoy their football and believe in themselves.
"We want to be strong at home and that means winning as many games as possible in front of our own fans.
"There's still plenty to play for between now and the end of the season so it's all about making the most of these opportunities."
Michael Gardyne misses out for Kilmarnock at Tannadice under the terms of his loan move from Dundee United.
Sean Clohessy (ankle) remains a doubt while Greg Kiltie suffered a knock on Scotland Under-17 duty and could drop out.
Long-term absentee Darren Barr misses the fixture with a hip injury.
Striker Kris Boyd is focused on getting Killie up the table from eighth place in the Scottish Premiership, starting against United.
"Where we were at the start of the season was tough for us," Boyd said. "But we always felt if we got a good run together we were as good as Dundee United, Inverness, Hibs, St Johnstone.
"We have struggled against them in the past. We know we can beat teams below us and the next test is to beat the teams above us. We have only beaten one team in the top six, which is not good enough. If we want to get in the top six, then we need to start getting results."
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- St Mirren
- Dundee United