Subaru's always sound tick like crazy when they're cold, it's completely normal. If it's a cool morning, I usually let the car warm up for around 30 seconds before I start to drive it. On a warm day, I don't wait at all, and just go. If it's winter, I usually let the car warm up for several minutes before heading off.

Rule of thumb, I drive it very gingerly until it gets to normal operating temps (keeping the revs as far under 3000 as possible). If you have a 4EAT, I would drive it normally, but don't rag on it while it's cold. I wouldn't put it in 2nd, as you are actually putting more strain on the engine to produce power in 2nd, rather than having it in 1st and have it shift to 2nd.

 

Sounds like the classic Subie tick.

 

I'll also throw out the possibility of a header gasket leak. They can sound like a lifter tap and once everything is hot and expanded, no more leak. Happened on a car of mine before.

 

Snow Drifter, 2003 with how many miles? Has the valve lash ever been adjusted?

Using a long screwdriver as shown in the below picture, whilst engine is exhibiting the loud ticking, start hunting for the noise. Place screw driver against the fuel injectors, valve cover, intakes manifold and exhaust manifolds.

 

My 03 Outback ticks more when it is winter and nice and cold. Quieted down after a valve adjustment at the timing belt job.

Also has some oil preferences that run quieter than others.