Toby (4/5)/Lady Garden (3/5), Pleasance Courtyard, Edinburgh

Refreshing: Toby perform surreal sketches while barely keeping a lid on their sibling bickering

Just when you think you've seen every possible permutation of sketch comedy – troupes of boys in suits or girls in matching frocks, sketches performed at super high-speed, to rock music or in gimp masks – the Fringe throws up another possibility. Toby are Sarah and Lizzie Daykin, real-life sisters who perform surreal sketches while barely keeping a lid on their sibling bickering. Having been spotted by the relentlessly innovative production company The Invisible Dot on the Free Fringe in 2010, they're one of the most refreshing and exciting new acts at the Pleasance this year.

Sarah is the self-styled star, a hyperactive, attention-seeking brat in a purple prom dress whose pursuit of fame has already seen her sign up to Kabbalah and enter the Priory for Haribo addiction. Lizzie, or "Sarah's sister" as she's known, is a softer-spoken type in jeans, T-shirt and a neat bob who has given up music school to perform with her sister, but finds herself constantly relegated to the tech desk.

Their yin-and-yang dynamic forms a compelling subplot (Do they really hate each other? How can two girls so different be sisters?) to a series of insane skits, videos and even jazz singing. There's a disastrous dinner date, which descends into endless culinary puns, a dance routine about puberty and an encounter with an old woman who waxes her cat. The pacing of these oddball, original sketches is expert – understated slow-burn rather than slapstick – and the family narrative builds up to a deliciously unsettling ending. A peculiar and extremely promising pair.

Lady Garden take a more traditional approach to sketch comedy in their prop-heavy, quickfire hour. It's the all-female troupe's fourth year at the Fringe and, having lost one member, Jessica Knappett, to The Inbetweeners, they're working as a five-piece for the first time. Directed by Phillip Breen, they've slickened up considerably performing on an eclectic living-room set crammed with glitter balls, gramophones and hat-stands, dressed in various takes on Land Girl tweedy chic. The opening is one of the best I've seen and there's a running joke in which everyday events are imbued with tragic significance, which is brilliantly done.

Enormously likeable – particularly the maniacal Hannah Dodd and the charming Beattie Edmondson (daughter of Adrian Edmondson and Jennifer Saunders) – their strength is that they all have funny bones and don't mind making themselves look as silly as possible. Their weakness is that they still lack the writing and killer punchlines to end every sketch with a bang. Still, it's going in the right direction and you'd have to have a heart of stone not to leave smiling.

To 29 August (0131 556 6550)