Had someone in to do up the stairs, done a terrible job so DP and I decided we would do it ourselves in future. Done the living room wall but I'm noticing gaps. DP said he will take off from the noticeable part and re-do, I'm just wondering is there a easier/quicker way to fix this? We are new to this wallpapering thing so it's not the best. I only noticed it yesterday but can't unsee it now. Photo of the gap attached. It's not too bad everywhere else.