KatLike said
does anyone have some tips for grafting? Super curious and haven't had much luck   

Grafting involves more than just looking up youtube videos that look so easy of what are mostly adds for people looking and mostly hoping to be viewed by farmers that will give them a job. What's missing are all the trade secrets of storing scions, all of which vary by type, and many other aspects as disease avoidance, and on and on. 

My best advice is try something very easy such as apple grafted on another apple first. When you pass that test you will at least know as much how to line up cambium layers before moving to something more disease sensitive or demanding in any way otherwise. This is where many here can help with ideas of whom to buy from because (moving forward) the best idea is to ask us about which vendors can supply you with a single test tree of dormant (held in a cold storage) quality that you can hack apart and re-assemble. 

I would at this point hate to be the one to name off qualified vendors not knowing which continent you live on..

Also we mostly hope you are not interested in grafting conifers or evergreens which I have never seen done at the HOS, because the methods and physics are known to be so vastly different than apples (ie. you have not mentioned what you failed at yet).

Then scions of apple don't have high requirements storing them in a cooler as to the way treating them as much as other types. Mailed scions in a dormant condition and put back into a fridge are very common. The stock of apple once received is not required to be cooled as long as the roots are potted up. Of which there is a big window of time of 8 weeks to graft the cold scion to the potted stock. Apples will want to go onto other apples, but some exceptions with interstem (double grafting) exist.

I met once with a person that had done all the above and failed due to not being aware where the cambium is. I have also met those expecting a perfectly good graft with all the proper surfaces mated up just right, but had allowed rain to ruin the project by introducing disease. With that I suspect one of those were your problem. Recognizing that the cambium is a very thin layer under the green colored phloem and the need for a shelter before and after a graft starts leafing out.

The most important is to keep your fingers intact. By this I mean well by.. please keep two fingers always touching (left vs right hand) and "feel" the slip. Eyes and motor control will not see fast enough.