If the carpet in your rental home leaves a lot to be desired, unless you are in a short lease situation, you should consider other options. The landlord may welcome a positive change such as lifting and removing carpet if there are decent floorboards underneath. Where carpet must remain and if money permits, purchase a rug from Ikea, Freedom, etc. to cover the ugly carpet as much as possible. Floating flooring is also an option, which you can place over the top of the existing flooring. Chipped bathroom floor tiles can be concealed with a bathmat and durable polyurethane mats can be used to cover unattractive kitchen tiles.
Flooring: floors can really change a space, so make sure your floor looks the part!
Another quick fix for aesthetic improvement is curtains
As mentioned in a previous post (Think Before You Act!) your home’s curtains may not be to you taste, so seek approval to take them down and either discard or store them. Shower curtains are a must to change as they can be unhygienic. Homeware and specialty stores have a range of standard sized roman, venetian blinds and bathroom curtains which can do the trick and allow you to take with you when you leave as they are standard fittings. Just re-iterating you must keep the original curtains to put back up when you leave.
Curtains: you can’t beat plain white curtains for a living space but why not go crazy for fun and colour in the bathroom and kitchen?