The couple made their debut on the dance floor last week, performing the Viennese waltz on the season premiere of the ABC show.
Writing in her OK blog, dancer Johnson said that building up Arquette's confidence had been important this week.
"I think that David takes himself really, really seriously, he's very, very hard on himself," she wrote. "I think that when he watches the dance back, he's so super critical. So for me the hardest thing is making him realise that he's actually really good and he's just gotta have that confidence on the dance floor."
Arquette and Johnson will perform the jive on tonight's Dancing with the Stars, a dance which Johnson said "really suits" the actor's personality.
"[The jive] is a really fun, fast dance," she wrote. It's really fast, it's fun, it's really energetic and that's what David is all about.
"This dance is physically exhausting so it's very hard rehearsing, because it takes a lot of energy out of you. David's so fit and I really think we're ready for it."
Johnson, who won the Mirror Ball Trophy with Hines Ward last season, also told readers of her blog that she and Arquette have been getting along really well in rehearsals, claiming the actor makes her laugh "all the time".
Arquette was supported at last week's taping by estranged wife Courteney Cox and their young daughter Coco, who he called "the light of his life" while speaking to Brooke Burke backstage.
Dancing with the Stars continues tonight at 8/7c on ABC.
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