I'd consider buying a furled leader off mrtrout on this forum. You can then add a similar length of straight mono, fluoro, copoly, whatever. Mucilin, or similar, on the furled leader, Leadasink, or similar, on the tippet, put it on, wipe it off, repeat as needed.
It helps enormously if there's an upstream breeze and the sun isn't casting your shadow towards the fish. This will happen about twice a year if you go every week

. Take your time to get to a position where you can cast slightly upstream of rising fish without 'lining' them. A bit of slack in the line is advantageous, chucking in an upstream mend might buy you a second or two extra drift before drag sets in. Wait until your flies are well behind your target fish before lifting off as smoothly as possible (this is where Mucilin on the furled leader helps). Use the eyes in the back of your head to judge your back cast to avoid "tree trout". Don't have eyes in the back of your head? Me neither so tie some extras!
When the inevitable happens and you get a take just lift into it and try to maintain a modicum of pressure as the damn thing flick-flacks across the surface before bouncing away to freedom. Repeat until you are happy, insane, or it's too dark.
If there's nothing rising, add a small weighted nymph to the bend of a dry buoyant enough to keep it up and fish "The Duo". It's like upstream dry with stabilisers on. You have to use all the techniques for upstream dry so you can practice avoiding drag, lining fish, casting shadows and the rest. If you arrive at a steady riser it's a moments work to snip off the nymph and fish in a manner The Piscatorial Society would approve of. Those fish are still there even when they are not rising and eat most of their food without breaking the surface. The rewards can be surprising. Here's one from yesterday.

I had one to the dry and six to various nymphs.
I still consider myself very much a beginner at this.
SharkeyP