Here are some examples you should take a look. They are all wonderful enough to provide a tree wall decorating idea for you.
Source: etsy.com
Tutorial: pepperdesignblog.com
Source: etsy.com
Source: mobilehomeliving.org
Source: greenblue.org
Source: joemonster.org
Source: justagirlblog.com
Source: yohyoh.com
Source: homedit.com
Source: etsy.com
Source: hammersandhighheels.blogspot.com
Source: homedecomag.ro
Tutorial: craftsbyamanda.com
Source: earth911.tumblr.com
Source: apartmenttherapy.com
Source: kids-room-design.blogspot.com
Source: swiftsorchids.com
Source: projectnursery.com
Source: constantchatter.com
Source: mosaicdesignideas.com
Source: thinking-stoneman.blogspot.com
Source: handmadecharlotte.com
Source: artideas.typepad.com
Tutorial: bargainbound.blogspot.ro
