These tips are not for everyone! some are only possible with certain privileges. I'm sharing in hopes that some parts of this will help people with a similar brain and life to mine.
1) plan your bedtime and train your body to a set sleep schedule.
This is possibly the most useful but also least accessible tip because you need to have a life that allows for this sort of regularity, so not everyone can do it. I did this by spending a month going to sleep at a set time using the supplement melatonin, and waking up exactly 7 hours later. You don't have to use melatonin, but it helps because it makes it easier to get up after 7 hours (or 7.5, or 8 if that suits you better).
Important notes on the use of melatonin: you only need 300 mcg (micrograms) which is a third of one mg (milligram), per night. Do not take more than this! It will not help to take extra and it can seriously mess you up, since it will make your brain think you don't need to make your own any more. Also, do not take it daily for more than two months or it can make you suicidally depressed. I don't know why but it had that effect on me and when I looked it up I was not the only one. To be safe, I wouldn't take it daily for more than 30 days in a row, and after that I wouldn't take it more often than once a week.
2) put your alarm clock/phone far out of reach from the bed.
If it's next to you, it's way too easy to turn it off or snooze it without ever fully waking up. If I do that, it will make everything else fail, so it's really important.
3) put everything you need in the morning next to your alarm.
For me, this is my meds, glasses, and water bottle. The meds I need to take in the morning I put in a bottlecap (to keep my cat from turning them into toys) on my desk so that I don't even have to open my eyes to take them because I can tell by feel, and I don't have to count or anything.
4) do everything you can do to get ready the night before, especially annoying or stressful tasks.
The more chores you have to do when you wake up, the harder it is to get out of bed. I gather together my outfit for work, including socks and underclothes and shoes, and put them all next to my bed. I put everything that I need to take with me (wallet, extra phone charger, etc) in my bag or in an extra bag next to it. I pre-make any food item I'm taking and put it in a grocery bag in the fridge so that all I have to do is open the door and grab the handles of the bag -- I don't have to check to be sure I got everything. I fill my water bottle and make sure my pill box is stocked and my contacts bag has lenses in it. If I plan to bring a drink in the morning, I prepare it the night before.
If you like fresh coffee/tea I would recommend that you set out the cup next to all the fixings, grind the coffee or unwrap the tea bag and put it in, make sure the pot has plenty of water, etc -- so that you have the least number of things to do in the morning. Make sure your keys have a home and are in it so that you don't have to look for them in the morning. I recommend a hook next to the door because otherwise it is too easy to put them down without thinking about it and lose them on the way to the door.
5) set a pre-getting-up alarm 20-30 minutes before the real one and turn on the light when it goes off.
This can be just your room light, or if you have SAD this is a good time to turn on a sunlight lamp and lay in bed with the lamp about 10 inches from your face. Either way, the time in the light will help to signal your brain to wake up and it will put you in a lighter sleep that is easier to get out of.
You can also buy an outlet timer and plug a lamp into it so that the light automatically turns on for you at the right time. I like using these because I also need the light on when it gets dark outside but I often have such a hard time switching tasks that hours go by before I manage to turn it on.
6) if you are caffeine-tolerant, get low-dose caffeine pills and take one with your first alarm.
This is amazingly helpful especially if you are unmedicated for your ADHD. It takes about 20-30 minutes to kick in, so it sort of slowly wakes you up like the light does. It is also helpful if you ARE medicated! I didn't realize how much it helped until I ran out of caffeine pills and was only taking my ADHD meds and it was at least twice as hard to get up.
7) eat a small handful of crackers/bread/simple carbs with that first alarm (or other small snack if you can't have carbs).
This helped me almost as much as the caffeine. It wakes my body up and also sets my metabolism going so that I actually get hungry, which is good because my hunger drive is much lowered by my meds.
8) if you have a smartphone, get an app that allows for gradually increasing sound and custom alarm tones, and make the sound something that is not startling.
I used to use the most annoying ringtones in an effort to wake myself up, but it was not as effective as a gradually increasing gentle alarm. It made me wake up angry and it made me more likely to turn the alarm off entirely because I couldn't stand the sound. There was also literally no reward for getting up quicker, whereas with the gradually increasing gentle alarm, I can avoid being annoyed by the sound if I get up quick -- and that is rewarding.
I use ocean waves or thunder as my first alarm, and then use a babbling brook as my second alarm. I set it to take 2 minutes to reach full volume on the first alarm, and 1 minute on the second.
9) on days you don't have an obligation to get you moving, use extra steps with the second alarm.
I use Timely (for Android), which has a "copy this pattern to snooze/dismiss" as well as an "answer math questions to snooze/dismiss" setting. My second alarm on off days is the only one I use the math setting for, but it's really necessary because otherwise I will just keep snoozing forever. If you don't have a smartphone or don't like this idea, you could put an alarm clock in the next room so you have to do more walking. I'm sure there are other ideas I haven't thought of.
10) if you take ADHD meds, take them with your first alarm on off days.
This is a really important tip for people like me, because it is so easy for me to get lost in my phone while in bed and not get up for 2-3 hours, if I haven't taken my meds. On work days I have to get up and get ready but I am not as respectful of my own needs as I am of work's needs, so I need my meds in order to keep from losing a huge chunk of the day. Also important is keeping a food bar or other easy nutrition in my bedroom for getting up on off days because I usually procrastinate eating until after it has majorly flared my ADHD.
11) if you are sensitive to cold, make sure your bedroom is warm enough, and warm your clothes/shoes if possible.
I don't know if this is true for others with SAD, but for me, being cold is HORRIBLE. So even when it is not really cold enough to warm the whole house, I use a oil space heater in my bedroom and I put my shoes as close to it as possible without touching. This makes it a lot easier to get up because putting my feet in warm shoes actually feels good.
When I remember, I will drape my clothes on the heater too but that's dangerous if you do it for more than 5 minutes so I can only do it when I am going to literally not stop looking at the clothes until I take them off of the heater. Another thing I've done is sleep with a warm robe under the covers next to me, and when I wake up I put it on under the covers as a way to transition out of bed.