Getting the right equipment can make or break your walk so it's important to make sure you're well equipped before you head out. Here's a list of some of the equipment essentials I use.
Waterproof jacket - There are many different jackets available from many manufacturers. From your basic waterproof to the more expensive waterproof and breathable material such as gore-tex or eVent. It's important you choose a suitable jacket for the conditions you may encounter. You may just need the hard shell or you may want to opt for a 3 in 1 jacket (outershell and removable inner fleece. You really are spoiled for choice. Personally I have a Rab Bergen, lightweight very breathable and waterproof. An all round good quality walkers jacket.
Base layer - Keeping warm or keeping cool, a base layer will help with either. Dozens to choose from and I've no real preference but I have always used Helly Hansen.
Rucksack - There are hundreds of different designs for rucksacks and lots of different sizes, so you have to base this purchase on what your needs are. For day walks I have a Berghaus Freeflow 30litre + 5 which I find really comfortable to wear and surprisingly roomy. The freeflow design means that it's not flush against your back so you don't sweat too much and with plenty of padding around the straps it's comfortable on your shoulders and around your waste. For longer distance walks or camping trips I go for my Berghaus Verden 65+10 pack. It's a great pack to use and with it's BIOFIT system it can be adapted to fit the wearer with the simple pull of a strap. With the weight involved in lugging your gear around on a camping trip it's important that the pack distributes the weight in the correct area of your body and this allows that..
Waterproof or quick drying trousers - If you walk in Scotland you are going to get wet, so lightweight, breathable and/or waterproof trousers should be high on your list of priorities. I use two different pairs depending on the conditions. If the forecast is dry or light rain I'll use my Nike ACG trousers. Although not waterproof they are quick drying, if it's a hot day you will benefit from the thin and lightweight material keeping you cool. Extra pockets mean lots of storage also. When conditions are worse and inclement weather is on the cards I'd opt for my waterproof Berghuas deluge over-trousers.
Fleece - Layering is very important and could keep you from having problems should the weather change for the worse. With a waterproof jacket on top and a fleece underneath you will be dry, warm and very probably windproof. There are hundreds of fleeces on the market so you're spoiled for choice but I use either a Berghaus spectrum micro-fleece or if the conditions are slightly worse the Berghaus Hobart windproof fleece. On warmer dry days you'll find that either could be worn as your outerlayer.
Footwear - Probably the most crucial piece of equipment is what you wear on your feet. Your spoiled for choice with what's on offer but it's essential you try before you buy and you wear the correct shoe for the walk you are planning. A Hiking boot is likely to kill your feet if you are trekking along a flat path and a trekking shoe will not give the support a boot would do if you are climbing a tough Munro. It's important you research the walk you are going on beforehand. I've found most of the Munro's I've climbed so far have pretty well constructed paths so you could manage with trek shoes or even trainers, however some such as Beinn Dorrain and Beinn a' Ghlo the path isn't suitable so boots are needed. I wear a pair of Scarpa ZG65 XCR boots. At £125 they are at the higher end of the scale but they are absolutely fantastic boots. I must have walked over 200 miles in these boots and suffered only 1 minor blister. Incredibly comfortable and waterproof I'd definitely go for another pair of these when I've worn them out. 10 out of 10.
Miscellaneous - A few other must haves :
A detailed map of where you are walking
A decent compass
A whistle in case you run into trouble
A torch
An emergency blanket
Lots of water
Lots of food